All the research I've done has pointed me in the direction of the 915 transmission. It seems that it's a better unit for my purposes (track events, autocross, street driving) than the Berg unit...which is a great unit for some, just not for my useage.
I recommend doing a search in this forum and
www.shoptalkforums.com for information on the 915 and Berg units and make a decision based on what you intend to really use it for, powerplant torque (the killer of trannys), and budget.
Either way you'll have various modifications that will have to be done to the pan and body of the car.
Again, for me...915 all the way. It's designed to withstand alot more torque than the T-1 trans which is what the Berg is based on.
Just my opinion for my application.
Hope your search goes well.
DORIGTT