I know, but if your getting a card such as a 7300, then the Intel and AMD rigs would be the same performance as either one will be held back, sure, you could upgrade later when you can afford it, but you won't be amazed by the PC's speed in LFS, as it won't be much quicker...
What about a 7600GS? are they really expensive? It might be worth getting the Intel rig, and then getting a new GFX card later, but if it was me i wouldn't bother and would save up till i could get a 7600GT....
EDIT - Like the above post says, get a E6300, and overclock it later if you want to