1> Will you overclock if yes then go for an E7200 and with the other 2.5k get your self a CM Hyper212. If not then go for the E8400.
2> I would not recommend a P45 if hes not OC'ing come on people if he's not OC'ing whats the point in dishing out so much cash. Instead get the Biostar P35 if possible or the P43.
From what I see people are very against AMD but thats not correct. AMD may not have a very good range of processors AS compared to intel but actually there platform is very strong like look at the 780G from gigabyte or biostar for its price look at the number of features like Firewire Esata and more sata ports compared to P35.
I doubt a processor would make hardly any differance in frames at the max 3-5 if not OC'd.
The choice is finally upto you. As to what your requirements are.