I have a brand new torque converter for a 700r4. I bought it for my truck but decided to go with less power so less stall.
It is a Spec Rite torque converter. They are excellent converters and they stand behind them 100%. Just as Big Jim He knows the guys down at the shop.
any way here is the link to the actual converter:
http://www.specriteconverters.com/pro_street_series.asp
It has 2500 stall and can handle some power.
I am asking 400obo plus shipping for it.