3095 e-maxx needs hardened ring gear

hi all. My question to monster staff is this. Which ring gear and pinion is best to buy as there are 3 different ones on the web site at varying prices? i am running mm combo 2200kv with 5 and 6 cell flight power lipos so original crown wheel did not last long on this power, mind you it has not done bad its the original one and its around 8 years old . also whats all this hot bodies diff i see on the web site? i trust they fit in original e maxx diff casing? one more question as they are not in stock how long can i expect to wait for u.k. delivery? thanks all, chris.