Yeah, heres my opinion
1) Drop the 4600. If you want to save money, get the 4200 by Asus (o/c's well) and Overclock it, it will be faster than the 4600 and cheaper
2) Buy the Radeon 9700 if you have the money. Its worth it. And I wouldnt worry about O/cing yet. Wait a couple months (or longer) and then do it. Stock this card smokes every card on the market easily, and to me O/C this right now is completly useless. Its all on paper what your worried about. When the time comes, O/C it. To me keep the warranty in mind for a few months. Whats the difference playing Unreal Tourn at 240 FPS rather than 210 ? You tell me. Things look good on paper, but come on
3) I would recommend Kingston PC3200....works better than Corsair.