I doubt you'll find anything from Prothane or ES that will fit out of the box, or I would have heard of it by now. I think the closest anyone got had the right diameter but needed to be cut down, if I remember correctly (which with how my memory is these days, take it with a spoonful of salt).
I'm running the Outfitter Design bushing kit. Having it mounted solidly to the chassis has been nice, plus unlike urethane that will break down over time the OD bushings are a lifetime part. It is more cost than urethane but they're very nicely made and go in easily. Getting the old bushings out on the other hand is a PITA unless you have an air hammer. Even then it's iffy.
Find many great new & used options and get the best deals for Polyurethane Front Differential Mount Bushing Set (3 Location) for Hummer H3 at the best online prices at eBay! Free shipping for many products!
I've done a bunch of off-roading with the stock bushings. Never had any problems. Sure mine was worn out at 150k...but that's not too bad. Easy to replace. Buy new ones on ebay for $12 or whatever they are. I wouldn't over-think it personally.