If you are going to have it stick out the back, you'll probably want to go Porsche, some of the guys on here know a lot about Porsche trannys, but they aren't alway on the forum to answer questions. I don't know about Porsche trannys myself.
Or, you can do what I did and use an 02M transverse tranny!!!
http://www.germanlook.com/Forums/showthread.php?t=4697
Jason