Hi Luke,
I'd say it's more accurate to say that the AMD x4 once overclocked won't be far behind the overclocked i3 (if at all) in FSX, but would certainly be faster in most other games and mean that your computer is more future proof for future games than with the i3.
To be honest for a straight gaming rig, a new gfx card in a years time probably wouldn't make much difference to you if you are still using your 19" monitor. Typically the native resolution of a 19" monitor is low enough that a relatively low end graphics card would happily run at that resolution and fairly high graphics setting without too much difficulty.
I'd almost suggest you next upgrade should be a nice hi resolution monitor?
Best,
E-I
Yeah, im now thinking that going with the X4 components will be the best thing to do as it will be a little more future-proof.I could then save some more money and buy 2 24" monitors and a 5770 or better GPU with eyefinity.