My First Build

hi there i am about to start my first build i have about £300 at the most to spend on it, i just need some help what parts i should buy to run fsx ok

i have already bought my power supply jeantech 350 120mm fan
bought my case from pc world
just wondering what pcu, amd or intel what is the difference and which is faster,
buying a cheap motherboard and getting a 160gb hard drive off ebay

please could you just tell me about the cpu

and im getting 2gb ram
and 512mb video card

www.newegg.com search there