Get HD 3650 from KMD, 79$, will come to close to 4-4.5k, excellent card, performance equal to 8600GT 256MB GDDR3. Also try to find HD 3690, which is slightly slower than HD 3850, best bang for buck. U dont need X1900XT for Watching Movies, Viewing Hi-res images, Vista Aero. U need silent, cool and GPU with H/W decoding, H264 Acceleration. Newer version of 8400GS has very powerful DVD features.
I would suggest a 8500gt or Ati 2600pro, the're cheap(4.5-5.5K) , locally available and are more than enough for you requirements. The ati also has hdmi out which would he useful if you ever decide to connect your pc to a Lcd tv. Just a suggestion - save the 1k and get a creative live sb 5.1 sound card.
Get an ATI card for your purposes, its UVD is slightly better then NV's as some one mentioned KMD can get you an HD 3650, get that its the best you can get.
Also if you dont want it for gaming why you opting for fatality editions ? and too of castrated chipsets like a 8500GT.
7600 GT is good for gaming, does not have Hi-Def video decoder chips like HD series amd the Geforce 8 series. I would choose the ATI cards, purely for their better and efficient UVD's.
I would go with Punjab's suggestion, its good enough even for a lil gaming if u ever decide to, and for ur requirements 3650 is a Very good if not the best VFM choice.
There is no point in investing in old technology (7 Series cards) , Opt for a hd 2600 pro or a newer hd 3650 instead with HDMI and you'll be content with it for atleast another year.