Haha, the CPU socket types aren't the same buddy.
Unfortunately there are no i7 CPUs for LGA 775.
You can get
this though.
Core 2 Quad 3.0 GHz 12 MB L2 Cache, probably better but not sure.
Also, people, notice how he said "It's just basically a major upgrade of my PC." He's upgrading, he already has the necessities for a computer probably.
But you do need to make sure your PSU can handle all this.
If you want you can change the motherboard and go for the LGA 1366 CPU sockets and the i7.
Prepare for frustration, too. It WILL take time to get this all working, so be patient with building and getting it to work.