You might find this an interesting read - esp the costs involved of the comparative makes unless you are confident of fitting in an alternative diff into your existing set-up yourself.

https://passionford.com/forum/genera...nions-pls.html

Only thing I would say is try out a car with the type you are thinking of if possible before you commit. You migh not want some of the 'characteristics' of the different types that you hadn't considered - depends if your car is solely for track or just road use with occasional track use