I use a number (14) of 8GB Sandisk and Lexar CF cards in my two 7Ds. All are UDMA. Some are older 300X/45MBs, others are newer 400X/60mbs. The 300X/45MBs are simply getting harder to find. Out in the real world I can't tell any performance difference between them, either in the camera or downloading. I also have a couple 16GB cards, same quality and makers, that I primarily use in 5DII, but have occasionally used in 7D when I've filled all the 8GB cards during a day's shoot. I've used Sony CF cards in the past, no problem. Haven't used Transcend or some of the others.
I'd rather spread a day's or weekend's work around on a number of small cards, than have everything on a single big card, for the same reasons as stated above. I have had a corrupted card (once... many years ago and my own fault for removing the card from the camera too quickly). But I also worry about losing one or otherwise having it get damaged. Thankfully that hasn't happened yet, shooting digital for about 8 years now. Sometimes it helps to have many smaller cards to do some organizing during a shoot, too. But mainly I just would prefer to keep any possible losses to a minimum... so multiple cards work best for me.
I try not to download my images in a hurry, such as "dumping" to a laptop on location. Therefore I want enough cards on hand for a full day of shooting, and 144GB will handle over 5000 RAW files from 7D, which is about the max shots I've ever taken in a single day. Most days are less, thankfully! Last weekend I shot 3000+ on Saturday and another 2000+ on Sunday, but had plenty of time to download and clear cards in between.
For batteries I only use Canon OEM LP-E6, but that's mostly because when I bought them there weren't any "chipped" third party clones yet. I'd feel okay using Sterlingtek and other known 3rd party brands such as B&H or Adorama sell. I'd be a bit leary about unknown clones off eBay or elsewhere. The LP-E6 are long-lasting.... I'd estimate they give at least 30 or 40% more shots per charge than the old BP511As I used before (in 50Ds mostly.... which are no where near as hard on batteries as 10D). I can do a full day's shoot without problem using a grip with two batteries, freshly charges. I don't use auto playback of every image or chimp a whole lot, never use the built-in flash, rarely have long exposures or mirror lockup, only occasionally use Live View, and have the "sleep mode" set on my cameras for a pretty short time (2 min., if I recall). As a result I rarely need to change batteries during a weekend's work, but usually do charge up each evening and put fresh ones in each morning.
I used to carry two BP511A backup batteries for every one in camera, now I only carry one LP-E6 backup per in camera battery. So even though the LP-E6 are more expensive, I've bought a lot fewer or them. Though, if I were not using a battery/vertical grip for some reason, I'd probably put two backup batteries in my pocket.
Coming from 10D and 20D, you are going to fill up memory cards and hard drives a whole lot faster with the 25MB RAW files of the 7D. Personally I'm lookng to upgrade my laptop to a 1TB HD (from 250GB) and have a total of 14TB of drives on my desktop and network (part of that is an OS/programs drive, another is partially used as a scratch disk by Photoshop, and a lot is devoted to backup, so actual storage space is about 8 TB).
LR4 and CS6 will be fine and a big step up for you... plan to spend some time getting acquainted with them. I'm still using LR3 and CS5, but will upgrade eventually (I'll let others help Adobe work the initial bugs out, been there and done that too often). Depending upon what hardware you are coming from, you might need a more powerful processor, 64bit operating system, graphics accelerator and/or more RAM on your computers to use these much newer softwares effectively.
Beware with the 18MP camera of some of your old habits. For example, if you are accustomed to viewing your 10D and 20D image files at 100%, doing the same with 7D you will tend to think the 7D files are "soft". The 18MP camera's files do need more sharpening than the lower res cameras did, but viewing them at the same magnification is ridiculous, but a common mistake people make. Viewing a 10D at 100% on a typical graphics quality computer monitor is like making approx. a 30 inch wide print from the file. Using the same magnification with a 7D's image file is like making a more than 50 inch wide print, then viewing it from the same distance. So back off to 50% (or whatever) and you'll like the 7D's images much more.
It sounds as if you don't plan to use it, but just so you know... the Canon DPP softare provided with the 7D no longer supports the CRW files of the 10D. I believe it will still work with the 20D's 12 bit CR2s, though.
Finally, you'll be tempted to try out all the "gee whiz" focus modes of the 7D when you get it. Go ahead and play around with it... then when you get serious dial it back to something simple at first and spend some time gradually learning to use some of the other specialty modes a little at a time. I use back button focusing and single point/center most of the time with my cameras. Shooting action a lot, I also use AI Servo the most, but switch to One Shot or Live View for more critical focusing situations. I find the 7D's Spot Focus mode for higher precision to be particularly useful for macro, shallow DOF portraiture, birds in trees. Zone Focus and Expansion Points I use less often. I virtually never use All Points/Auto Selection. Speaking of macro, used with Canon macro lenses that have USM, 7D has a special macro focusing mode that kicks in automatically, but only works in AI Servo. That wasn't documented in the manuals that came with my cameras or any of the books I bought and read about 7D, but was discussed in a Canon white paper. That might be useful, if you shoot macro, and actually use AF and AI Servo with it.
