Looking for advice on new memory purchase

To make a long story short, its time to buy so more memory.

I've currently got 2 Sandisk Extreme III 30mb 4gb CF, 4 Sandisk Extreme III 4gb SD cards. I'm currently using a 1D mkIII as my primary, and plan to pick up a 1Ds mkIII once the IV drops and prices come down a bit more.

I've got a few options that I'm having a tough time deciding between:

1) 8 Sandisk Extreme III 30mb 4gb CF, 4 Sandisk Extreme III 4gb SD cards - $392.00
This would be sticking with what I know, and also gives me the most memory at 48gb. Also gives me a bit more protection in that if a card goes bad on a job, I only lose a small chunk and not the entire thing. along with what I have that gives me 36gb for each camera, albeit with a ton of memory changes which sometimes come at the worst time.

2) 2 Sandisk Extreme Pro 16gb - $349.90
This would give me, and I'm just guessing here, around 1000 shots on the 1D, more on the 30D, and probably half that on the 1Ds. I would also be less likely to have to change cards covering weddings and events, which is always a good thing. I'm worried the most about coming home with a bad card.

3) 1 Sandisk Extreme Pro 32gb - $297.00
I know with this card I'd never have to swap covering events and whatnot, but even more petrified of losing photos. This card would give me a ton of photos, even on the 1Ds, and would be very handy if I do end up picking up a 5d mkII for video.

For options 2 & 3, the SD cards I do have would become JPG preview cards, and the 2 cf cards would go into a small bag with the 30D as more of a walk around camera (until I get it converted to IR).

I'm also planning on picking up a pair of colorspace UDMA drives for on site backups (I've got a pair of 500gb sitting around), so I'm not as concerned about redundancy at this point.

Take a look in between those at the SanDisk Extremes, rated at 60 MB/s. I find that with the 1D3 a 4-8 GB card gives me a manageable number of frames on each card. With the 1Ds3 I'd definitely go for at least 8 GB. Also remember that the 1Ds3, unlike the 1D3, supports UDMA, so will be better able to clear the buffer quickly with UDMA cards (although everything you've listed is UDMA, not all your existing cards may be).

Very good points Jon, I didn't think think to check into the extreme III's being UDMA, so that counts option 1 out as I want to be able to dump them quickly.

I had originally looked at the Extremes, but started to look at the pros for the increased speed. But looking back at the Extremes, maybe I'll grab a bunch of the 8gb cards instead for the 1D, and grab some 16gb for the 1Ds when I get it.