Amd or intel

Depends on the use but in terms of low budget, AMD normally rules that relm.

Motherboard : MSI 790XT-G45 AM3/AM2+/AM2 $90.00
http://www.newegg.com/Product/Product.aspx?Item=N82E168...

Processor: AMD X3 435 $75.00
http://www.newegg.com/Product/Product.aspx?Item=N82E168...

+$15 for shipping so you have $20 left to add to your Video Card budget.

It is AM2+ motherboard so you need DDR2 RAM but if you prefer AM3 motherboard then this:
Motherboard: MSI 790GX-G65 $125.00
http://www.newegg.com/Product/Product.aspx?Item=N82E168...

But you have to shelve out $15 more for shipping unless you can find a combo.

Both motherboard have "unlock core" feature so if you are lucky you can get a quadcore out of the X3.

http://www.newegg.com/Product/Product.aspx?Item=N82E168...

http://www.newegg.com/Product/Product.aspx?Item=N82E168...

I got this combo new in box, I will sell for $200

Hands down. This deal is good....  

go for some phenom ii x2 processor with core unlocking motherboards(if they are cheaper) or the asus motherboards tom used for unlocking.Second wpuld be better choice.

Yep +1 for getting good mobo from which you can unlock cores and PII X2 or PII X3