I am asus fan myself but i would change the mobo, u can find this great
Gigabyte GA 965P-DS4 for £111.59 in scan. Better board and the Heat Pipe Design should aid u to control the temperatures especially if u intend to OC.
Scan says the Asus PB5 does not support more than 1 SATA disk in a RAID configuration internally, u should confirm this.
Well if its better, and u should have no doubt it is, the only question left is can it be afforded
anyway u cant go wrong the e6300 is a great chip and it wont let u down.