15% huh?
I would say fina/winny right now. Hell, really I think you can get down to like 7-8 % with just diet and ECA,no anabolics, but it does make it easier and more fun.
Save the t3 for like when you hit 8% and want that 6% or something.
Its all bout DIET! With that fina/winny combo you could add some LBM and drop all the fat you wanted. Even one or the other by itself would most likely be sufficient.