I talked to Keisler last week about my SS700. It is being checked out at Legend gear because of the problem I had with it dropping out of 5th gear.
The transmission shifted nice, and I like it except for the 5th gear problem, so I hope they get it fixed ans send the trans back soon.
Keisler did say they were developing a new tailshaft with the speedometer port moved forward so it dosen't come out right in line with the "B" body crossmember.
I also discussed the fitment issue with using the dropped transmission crossmember.

http://www.keislerauto.com/ss700.html

If you don't mind doing some fab work on the trans tunnel, a 6-speed is about the same cost?

I'd love to see the Passion 5-speed hit the market. Sounds like it would be a easier (no cutting) swap.