What's the best way to spice up sauce?

Rooster sauce

Get yourself some chili tepins, crush 'em up real good with a mortar and pestle, dump into sauce and simmer for a few minutes. Chili Pequins also work, but aren't as in your face heat wise as the Tepins.

Your 1 stop to hot Ghost pepper powder
Try something like this
http://ghostpepperstore.3dcartstores.com/Pepper-Powders_c_11.html