If that were my car and i had put the time and MONEY into that nice engine build, i would have gone w/ something NO SMALLER than a T3/60-1, but i would have leaned toward twin T3/67s or possibly something ball bearing. You're going to have amazing spool and a lot of useable power w/ the ones you have, but they're going to limit the amount of power you can make. I"m not sure what your goal for the car was, but i would have at least gone w/ a little more efficient turbo setup...just my .02
The problem that i see with those turbos is that the compressor side isn't the best or newest design on the market. The inlet is a straight 2.5" whereas the turbo i'm running on my turbo Honda is a 4". It would make a pretty large difference if you plan on running more than about 12psi (or wherever their efficiency range is). Having a larger compressor inlet, even on the same size wheel, is going to increase low end spool and make it more efficient for longer.
Here is the difference in the two turbos i've used on my car...this will give you an idea of the physical difference. I'm not saying your setup isn't amazing, becuase it is pretty damn sweet, but i'm just throwing out a few ideas to make it better.
