Porsche 986 trans

I've had some advise that the 986 Boxter trans is a good one to use. Has anyone used one? What code letters/numbers should I look for that would have the LSD (or do they have them)?
I've also heard the 6 speed is stronger than the 5 speed?
Yes, quite a bit stronger. I do work for a local Porsche dealership mechanic who races a Boxster. In the class he runs he has to use the 5 speed and he keeps a couple of spares under his work bench as they break often under race conditions. I have been in the shop when he has one apart and often there are gears with teeth broken off.