Upgrading my pc, and turning the old parts into a new pc

[luandro]

I have a kinda old HP Pavilion a250n. I want to upgrade everything, maybe just not the processor, and make a new pc with the old parts. So I'm basically going to buy a new computer, but the thing is ,I want to keep the old p4 processor, but find a decent motherboard to go with it.
I already have the drives and everything, I just need a new motherboard and new pc case ( which I'm also not sure, how it has to be). The other stuff I can get easily. What I really want to know is if there's a good motherboard with a 478 socket, and AGP 8x, and that supports DDR2. For the new computer I'm going to buy an old 478 CPU, insted of a new one, and put my old memory and everything. If there isn't such motherboard, what cheap new processor should I buy, that supports a good motheboard?

 

[Lax]

what cheap new processor should I buy, that supports a good motheboard?

I think you mean what motherboard should you buy that supports a cheap processor.

I am pretty sure no S478 board supports DDR2. As for finding a good board almost anything will work seeing as how 478 has been phased out (almost completely) so basically the cheapest board you can find with an intel chipset would do you fine if you're upgrading. What motherboard does the A250N have in it now?