If there is any advice I could give to anyone, it would be avoid cheap power supplies. They are cheap for a reason, and have the ability to destroy anything that they are connected to (CPU, RAM, GPU, Motherboard, Drives,etc..).
Its better to spend a little more up front, than to have to replace your entire system (and perhaps house) later.
Cheap PSU's also generally cause more unexplained system crashes than more expensive reliable PSU's.