Extra capacity transaxle covers

I'm still getting my 2007 ram 3500 drw 5.9 diesel 4x4 with an 8' bed ready for a TC and thinking of an extra capacity cover for both transaxle's and transmission and using royal purple lub. Allready got bilstein shocks and steering stablizer 6 Michelin tires. According to my door sticker I can carry 4806 which includes passengers inside for a total weight that I can carry. I had a torklift super hitch installed and plan on torklift tie downs.