Im using the IB, you can see how I fitted them here
http://www.oople.com/forums/showthread.php?t=20375
I went from the original oversize track power 3200 20C to these 4200 30C, the power difference was very noticable and I can fully recommend them...but the extra power has given me a reality check,for my level of driving ability Ive just dropped from a 5.5 to a 7.5 !
You dont have to mess arround fitting them how I did in the above link, if you dont mind putting the terminals at the back of the car and having longer wiring.
I have weights on the bottom of mine to locate them.
Having said all that I cant see anyone selling them at the moment ? !