One of the options for the Kuerigs at work is Green Tea. I go for one of those (like just today) when I want caffeine, but less than coffee or other teas. Green tea also has theanine in it which is calming (not an aim of mine). If you're looking for a supplement for the latter, check out Suntheanine.
If the aim is to lose weight, here are a few supplement options less often considered that may help.
Guarana. Read some of the reviews for this. Some, women in particular, say it helps them lose belly paunch.
Forskollin and L-Carnosine (not together). Both of these, especially Forskollin, will have you...pardon for the expression...$#it for Texas! I find both of these a bit too much and easier just to eat less to begin with. But you'll feel lighter on your feet.
L Carnitine Fumarate - This, like Guarana (but not in the same way), will help put ants in your pants...more activity, burn more calories.
And if you ever find yourself in a rowing competition, try Glycine Propionyl L-Carnitine! Max dose of that and you'll climb the walls! Like being a Border Collie, you'll have to have something very active to do or you'll go nuts!