What is an excellent power cable?

Kimber pk 10 And 14, use shiva, blue heaven both Nordost , powerchord used..,

Audioquest Thunder. It may be a little over your budget.

Do the sonarquest power cord connectors make a difference? 

Triode Wire Labs. Some of his product comes under your limit.
Also, try thecableco.com. They have a lending program where you can try out some cables, and all you have to pay is return shipping and a 5% restocking fee.

All the best,
Nonoise

I would check out a Magnan. Ken Stevens from CAT was at a demo here in Indy and bought for his entire system