Well, I've found most people who dis ATI cards have exclusively owned Nvidea for a very long time. Many are just parroting "stuff" they've heard. That said, I'm not telling anyone not to buy an Nvidea card. (OK, I'm saying not to buy one right now. lol) As a matter of fact, if for whatever reason you don't feel comfortable buying an ATI card, then definitely don't do it. It's your money and it's all about you being happy with how you spend it.
Right at this point in time, when it comes to direct x, Nvidea is woefully behind the current state of the art. For gaming that's a very important feature. Their top of the line cards you've mentioned, the 295/285 don't even implement Dx 10.1 (which has been around for a couple of years or so), never mind Dx 11. I would wait for the gtx-480/470 to be released, if at all possible. They will most likely be kick ass cards.
Now, if you plan on running Win XP (not likely, but just incase) then go ahead and get a 285/295 card. XP only supports Dx 9 and those cards are fully capable of running Dx 9.
If I really needed a new card today and just didn't trust the ATI cards I'd probably just buy a GTX 260-216 or GTX-275 to hold me over until Fermi was released. If Fermi takes forever to come (at this point who really knows) or bombs you can always pick up a 2nd card and run SLI. If I was going to go dual GPU I'd probably go with this PSU though.
http://www.newegg.com/Product/Product.aspx?Item=N82E16817256058Only $20.00 extra dollars and the extra 100 watts could come in handy.
Keep in mind that there are probably 10 other motherboards, PSU, cases, etc... that are perfectly good pieces. I like gigabyte, I like Silverstone, etc... Some people would consider those 2 terabyte 6Gb/s harddrives complete overkill and a huge waste of money. Or the SSD (Or they might prefer an Intel SSD). I wouldn't dissagree with them. Except that at this point in time with all of the advances in other hardware the HDD is probably the biggest bottleneck in most systems. In the end, this is just the PC I'd put together for the budget. I think anyone would admit that it'd be a pretty kickass computer. For the dollars I believe that this would be the fastest overall system you could buy today (If you OC'd it to bring it to it's full potential) and also be as future proof as possible.
I missed earlier where you asked about sound cards. Sorry, but I don't really have an educated recommendation. Onboard sound has always been satisfactory for me with a computer.