Or HPISavageForum.com. The guys know savages and are ridiculously friendly. For motor you will need to give a budget. If it's unlimited then this is the right forum and brushless is the way to go. 35wt is about the weight you will want in the stock shocks i think. People may say higher but if you are jumping you will start bending shock shafts.
As far as the diffs go . Check they aren't leaking before putting them in the truck and go to hpisavageforum cause there is so much that needs/can be to them it's silly.