Advice on diffs and diff cups

[tomato]

I got some money to do some upgrading. First you should know that I'm running and HVmaxx with 7 cells 3300's. I've put the UE idlers in already. I plan upgrade the motor at a later date. I do have a blown diff. What I'm wondering is if I should replace the DIFFS with UE ones or go with just the metal cups. The gears inside it are toast so I need the cups and a rebuild kit for the front and rear. Should I just buy the UE's and be done with it or do I save a few dollars and get the upgrades and rebuild kits. I DON"T want to do it again. I'll PAY MORE to have it last it's only going to be a couple dollar difference. Will the Stock shafts work with the UE diffs?

Thanks in advance guys.