So given that its a 15A surgeprotector I'll be ok untill the demand for current exceeds 15A? If that the case I'll be fine since this will only have the pre pro and sources on it, the amps will all be on the other 20 guage line.
I had a powerbar once, tasted great and gave me lot's of energy too. The Apple flavor is my favorite, although I wouldn't suggest you stick it in a 20 Amp circuit unless you like toasted/melted powerbars.
You will be fine on that circuit with plenty to spare.