Im going to go with the K-Go (vendor to be determined). I am guessing from peoples advice (THANKS A MILLION TIMES OVER!) that there are different "K-Go" makers and manufacturers? ...
With Chinese stuff, there are clones of knockoffs and knockoffs of clones. Everyone clones and knocks off everyone else. There could be 5 different products made by 5 different manufacturers, all made in the same factory on the same production line. The rules are different there and the rules about knockoffs and clones don't necessarily apply in China the way we apply them in the U.S. or Europe. One company might have a good reputation, and another company you never heard of will come along and make an improved version of it. So the knockoff is actually better. That's the way it went with the eGo and the kGo.
The kGo is a clone of the eGo, except it has more power. I don't know exactly what company was the first one, or if there is any significant difference between them. It really boils down to where the vendors get theirs, their judgement and how/if they've tested them. SLB is a well known manufacturer and if any of them are less than good quality, SLB wouldn't be one of them.
Brent at Hoosier has tested his pretty well, has most color options and there's a video on his kGo page that might be of interest. That's not to say any of the other ones are substandard. They could very well all be SLB models too. I think the one at Dark City is for sure. It's just that, IMO, Hoosier has the best deal on them right now.