Well, since you already have a Spearco FM setup on your car, I would probably go with a TA-49 if if was me...It'll be cheaper than a TA-33 and will flow better and make more power...or you could go with something a little bigger than that...
I would give John Craig @ Limit Engineering a call...He does real good work on these turbo's and if you tell him your setup and what your future plans and expectations are, he could give you suggestions on what to get...
btw, are those the 30# greenstripe injs you have??? If you go to a bigger turbo, your injs will be a little on the small side...An inj upgrade to at 36#s or 009s will be needed...Maybe even 50#ers depending on how fast you want to go...