I did this stuff (sad it had to be an ini edit, but it was made with the consoles in mind and restricted out the factory because of it) and my PC runs it fine @ 1680*1050 with EVERYTHING maxed out.
My PC would only cost about $500-600 to build now. When I built it I paid about $900 a year and a half ago.
The thing is, you can use this to make it easier on your rig as well. Like in Oblivion, turning everything on max, then using INItune to reduce grass density. Almost no visual difference but a gain of about 10-15 fps.
C2D E8400 processor (6mb l2 cache, 45nm, 3ghz, 1333mhz fsb) 4gb 800mhz RAM of decent make 9800GTX 512mb
Easily the most cost-efficient system you could build right now. Will smash *any* game out at 1680x1050. I have that spec except with a 8800gt and I can run Crysis on high with 40+ fps and gmaes like Fallout 3 and Farcry 2 are no sweat at all.
I suggest you find more sources. There are many tech forums where you can get many and varied options, rather than just one persons options.
Personally, I prefer the HD4850 over the 9800GTX. I chose to support the underdog and haven't had many problems after some driver updates.
It's interesting, the 9800GTX dropped in price immediately once the HD4850 hit, good think AMD is preventing NVIDIA from overcharging like they always do.
What kind of PC rig you need for this to happen? Let me guess. A very expensive one.
I can confirm this method is highly effective and MUCH appreciated.
As with Olbivion the textures at distance looked awful, but this really fixes it.