Which psu would be compatable?

I have a Lenovo with a Lenovo hombay mother board, a gt 545 gpu and an i7 cpu also i need a cheap as possible 400-500w one

Guest

TBH I would never recommend cheap n cheerful PSUs. They are the one thing that if it fails you risk tasking the rest of the equipment with you. It really isn't worth it. Far better to pay more and get a well known branded version, corsair Coolermaster Seasonic, Antec enermax XFX etc
Something like this would be your bare minimum
http://www.cclonline.com/product/99687/CP-9020009/Power-Supplies/CCL-Choice-450W-80-High-Efficiency-PSU/PSU0505/
HTH
David

David