I recommend the Bayou KAB6. It's more money compared to the others, but it's stout as heck, has no problem securely holding a keggle and will get you to a boil in no time. Others will work as well, just make sure you're aware if they have to be modified to safely work with a keggle.
I also strongly recommend considering welded over weldless. While a lot of people are quite happy with their weldless setups, many others fight leaks and eventually look at either a soldered or welded setup. When you look at the cost of having a 2-3 couplers welded in, it's fairly comparable to a weldless setup...especially when you have to buy twice.
I always say...buy once, cry once. You'll be happy with the keggle, for sure.