I've tried just about everything out there - I was very sad to see Adipokinetix taken off the market a few yrs ago, but of what is available today, T-rex is a great thermo, Cardio Breeze I guess technically is a thermo, but there's no buzz or jitter effect at all. It just sort of wakes you up. If you want to sweat like crazy, and I didnt' really notice jitters but you definitely feel the kick wash over you -- VPX Redline.
As far as aspirin catabolic effect - hadn't heard of it - I used to build my own ECA stack but I think I pushed it too hard and really toasted my adrenals on it and have just made a point of staying away from it. I sort of look at it that if I have to worry about catabolism from aspirin, when you are going to experience an amount of catabolism from the whole cutting process for competitoin, you don't have enough muscle to start with. I guess if I am worried about things on what seems to be a negligible level, then I just really don't have enough to start w/ and maybe should consider a more serious bulking phase first.