Well, you may have noted this, we really need a dollar amount on somethinig to go by. I can suggest a $7000 PC because you said price isn't an issue. With a 50 flat screen you shouldn't have money issues. I would say go for a Dell XPS. I have always liked Dells. I own 4, but recently I built one just for the cheap price. Go to
www.dell.com and build an XPS 800(or whatever the best model is called) and pick your options. A 7800GTX is a must. If they have the new 7900's, which I doubt, get one of those.