I haven't used Combustion, but I have read pretty good reviews about it. Combustion and maybe one of these, as to avoid huge amounts of caff and maybe add some mood enhancers, better feeling
Epitome
SYN-30 by SNS
βAIBA by Antaeus Labs-
I will be trying all three of those, but Baiba will be my first choice. Have been reading some good info on this and reviews coming back are pretty positive.
I know there are others out there but, I would use combustion and then add the mood enhancement- just my .69.
hope that helps