Price vs. Performance for FSX System

Hi all,

I am going to be building a system for FSX around Christmas. It will feature a Q9550. FSX is supposedly CPU bound so I'm allocating much of my budget in that direction. Currently I'm thinking of a 9600GT. I've been looking at video cards for a long time, waiting for price drops, etc. Here's what I see...

*ATI (in general)- I've heard that nVidia performs better in FSX
*4650- enough power? don't know enough about
*4850- price is doable. but heat?
*9800gtx- I've been waiting for the price to fall but they are still around $170 on newegg with rebates
*9600GT- enough power?

I don't know what to do. Basically I'm looking for a card that won't bottleneck my CPU in FSX. If the 9800GTX prices would fall, that would be a clear cut winner. Help!

Jeff