anyone have a recommendation for a new trans in a 91 350 Formula that will last a long time?

i had the 700R4 rebuilt a few years ago,it has a stage 2 shift kit in it which worked well for a while.the guy told me it would last as long as i owned the car.well,it's done now.i'd rather not pay 2-3 grand for a 2-3 year transmission.

i drive it every day,only on the street,the motor is stock.
thanks for any suggestions.