Can you afford the thousands of dollars for the 5D Mk II?
Get it, then, if you can.
But for your first DSLR, it would be a waste. Here's something: it's a PROFESSIONAL camera! While you might be able to learn all the features, that's still a common misconception. It's ALWAYS better to refer to a entry level when starting out and then progressing - even if you have the money.
I suggest getting an entry level DSLR. Here are my suggestions:
- Canon EOS 450D/Rebel XSi
- Nikon D40X/D60 (do not consider the D40, there's not much point)
- Maybe the D90 if you can afford, although it's an advanced amateur camera, more suited for those in between semi-pro/enthusiast and entry level
Sony, Olympus and Pentax have their pros, but I really suggest a Nikon or Canon to invest in, and to start off at least.
D90 has video. Not great, but it's HD.
It seems you have a lot of money... your range stretches a fair bit! The D40X is around $400 and the 5D Mk II is around $5000. So, I wouldn't get the D40X. I'd get the D60/D90. More features, and after all, you can afford it.
Still, no auto focus or live view means you'll get used to doing it the hard way. The original way. Heck, it might help you get better at photography. But almost all Nikkor lenses suitable for D40X/D60 are AF-S (auto focus).
As I said, no live view or auto focus means you'll learn to do it the harder way and thus get better.
But look, you can still use manual focus.
The D60 can comes with AF lenses, so it's fine, anyway.
If you can afford it, the D90 is the best out of what I've recommended. It just has the best quality in terms of image quality.
Otherwise, the 450D.
Remember, I wouldn't exactly trust new things, like HD mode. Wait until it develops... but as you said, you already have a camcorder, so it doesn't matter.
Live View has been rather impressively improved on the D60/90 and 450D/Rebel XSi. But of course, nothing beats the viewfinder. Use it most. LiveView in awkward situations or hard to see, such as macro.
All I've mentioned, but esp. the D90 and 450D have excellent low levels of noise at higher ISO levels.
Just buy into a brand and once there, don't turn back. For many, it can cost over tens of thousands to change brand. Of course, it depends when, exactly, but I'd advise sticking with a particular brand once you buy it.
Misinformation on the misinformation
The 5D is in fact $5000. Don't always assume... it IS $5000 here in Australia.
Canon may not consider it a professional camera; there, I am wrong, if that is the case. I don't own the 5D.