Joseph Locicero :
Well the motherboard model is a dell 088dt1. and also next to the 4 pin cpu connector it says ATX12V 2...so? thank you
You didn't mention how much wattage you'll be needing either, so I picked this one.
;http://www.newegg.com/Product/Product.aspx?Item=N82E16817153173
If you want something more specific let me know, however this will run more then what you'll probably need with room for upgrades. If that's suitable then select a solution.
Make sure you have enough space in your case for a ATX PSU as well!