T56 Magnum should I buy and where?

[FETorino]

I keep doing more research and every trail seems to end with a close ratio T56 Magnum.

My car will have close to 700hp and over 600 ft lbs of torque I know that.
6200 rpm is the target for max hp.
My car will see some street miles including highway driving.
My car will be track oriented, I will drive it at both open track days and hopefully RTTC and other similar events.

Is there any other viable choice for a transmission?

Anyone have a preference on vendors. I was thinking of purchasing it thru LIberty. any reason to go elsewhere?