jdnan wrote in post #18573775
I'm another one of those typical amateurs with gear questions. I've read through dozens of threads and they're all different situations than mine (of course) & I would love some feedback specific to my current setup and alternatives. I used to do a lot of sports photography with the 1D MK IV & EF 300 2.8L IS w/ a nite flash setup on a monopod, plus a 1D MK III w/ a 70-200 IS II. When my youngest graduated from high school I sold the 300 & MK III & haven't taken more than 20 or 30 shots a year for the last 5 years with my DSLR. We moved last November & my new backyard is a 50 acre nature center with abundant wildlife, including some very nice hawks, owls, cranes, ducks, etc. This has reinvigorated my interest in photography & I've decided it's just too convenient not to go out & shoot on a regular basis, but I want to upgrade my gear, mainly for reach, often in low light situations.
LensesI'm definitely going to acquire a lens w/ some reach and am torn between the Canon 100-400mm II (or the Tamron G2 version) or springing for a Tamron 150-600mm G2. Maybe even a 400mm 5.6 prime?
Camera bodyReally leaning toward grabbing a 5D IV refurb for the long lens keeping the 70-200mm on my 1D MK IV for the closer shots, but trying to decide if I can be happy with just my current camera body & a longer lens. I'm looking for something that will give me high ISO performance on shots that can be heavily cropped & still get a nice size print to decorate areas of the new house. I've read that some folks think that the 6D II (with all its drawbacks) might get me what I want in ISO performance at a more affordable price. I'm thinking since the MK IV is already a crop sensor (1.3) that I'm not going to get that much improvement w/ a 7D II as an alternative, but maybe an 80D?
All thoughts & opinions appreciated.
Never mind, AFTER I wrote all of this I then saw that you had your "GEAR" as a link and I saw that you already bought what you wanted. Hopefully you're having a good time with your new place and your new camera gear! 
Jerry,
I have what you might want, and I am happy enough with what I have, of course if money was not a problem I would get a 1DXII and a 600mm L lens...\
I have a 1DmkIV, I love it, but it's LOUD, like I have to tell you, it can literally scare skittish wildlife away.
Also, I have the 7DmkII, the comparison between the two is quite a bit, it has a lot of the newer electronics in it, it is a LOT quieter, not silent, but a major difference. It does well in low light, I rarely try to shoot in low light, but it is very good.
If you want to get a full-frame like the 5DmkIV I would go with that, I want one myself, so I can see why you would want one. I have a 5DmkII, but that is NOT a wildlife camera, super slow and very clunky! ALTHOUGH, I can put on any of my long lenses and I get a super sharp image, better than my 1DmkIV or 7DmkII will give.
Hence my reasoning for a full-frame 5DmkIV, from what I have seen they do get you what you are after.
I also have the first version of the Tamron 150-600mm, that also is a VERY good lens, especially for closer stuff, I mean, it's however you set it up in your lens calibration really. I get some of the sharpest shots when it is under 45'. It's a slower lens for 'birds in flight' (BiF) but it's definitely doable, I use it all of the time.
Another lens I have is the Canon 400mm L f/2.8, it's really similar to your 300mm that you sold, so you know what that can do. Paired with a 7DmkII or a 5DmkIV it would do the job, not that you asked, but just in case. I rarely use it because it's so heavy and I shoot mainly hand-hand.
The main lens I use on all of the above cameras is the Canon 100-400mm L vII, that is 'almost' equivalent to my 400mm f/2.8 lens. The reason is, image-wise, it is as good, but the drawbacks are that if you use a 1.4 Canon vIII extender it only center focuses, which is not bad for flying birds really, but if you use it for static birds like I also do, it can be not so good. I am used to my 400mm f/2.8 lens, I can do BiF shots with my Canon 2.0 vIII extender and use any focus point I want.
My choice if I were buying like you would be the 5DmkIV and the 100-400mm vII, you will get very good quality images for that, I have checked it out quite a bit, I like what I saw.
Maybe you can rent a camera and/or lens to see what you think is best, that would be the ideal thing to do, but if you are like me, I'm too lazy to do that. 
I am not trying to get you to look at my Flickr shots 'just because', but I have a lot of shots with the 7DmkII and the Tamron and the Canon 100-400mm vII lenses that you can see for yourself, it might help you some. That's what I do when i am wanting something, I go to Flickr because it has all of the exif information and you can skim through the shots really quick
(See my Flickr link below in my signature if you want, or, go there and search for the camera/lens you want and you will see a lot)
If you want to see a side-by-side comparison...
http://snapsort.com/compare
Here's another very good place to see what the difference in each camera's sizes are.
http://camerasize.com/compare/#153,154
I really envy your excitement especially with all of that land near you, I wish I had access to that kind of stuff. If you feel like checking out another place that has other stuff that you might be interested in, check out VCDB, (Village Creek Drying Beds) over close to Six Flags, it changes with the seasons like most places, but it is one of the best places around that area, I just moved from Irving to Paris, Texas and I miss that place a LOT! I have the best photography memories from there.
https://www.google.com …4985m/data=!3m1!1e3?hl=en
or...
32.779384, -97.126672
I hope this helps some, if I can help you out in any way, just let me know. 
Randy