I think you might be able to get a better value on PSU. The system you describe doesnt really need a $200, 750w unless i missed something? I know the efficiency is nice... but getting 80 PLUS GOLD Certified tacks like $100 to the price.
I would suggest you consider a single rail 80 plus silver modular Corsair. They still have good reputations for a lot less money.
http://www.newegg.com/Product/Prod [...] 6817139010
Also consider getting a lower power one, many people overestimate what they need. Low quality PSUs inflate the wattage to look good--with the high quality ones you are interested in you can afford to go smaller. Single rail PSU calculator:
http://www.corsair.com/psufinder/default.aspx
I also agree that the 9800 gtx is a dated card. Right now it IS good performance for the money, although a bit of a power hog. You could get a newer more power efficient card that would save you money in the long run--since it looks like you prefer to spend a lot and keep your builds for the long haul.
I think you should consider starting with a newer model card would still be around in a year if you wanted to add a second for SLI. (If I had an SLI capable motherboard this is definitely what I would do.) Since a mid-level card seems to cover you at the moment, you could get a single 4770 ($99) or 5750($129) and add a second when you want the power. (as noted the big difference between the two is that the 5xxx series has the benefit of DX11)
One of the reasons I am a big fan of Tom's is the articles on "best _____ for the money" The last video card review was September, but another (including the new 5xxx series should be coming by the time you build.
http://www.tomshardware.com/review [...] ,2404.html