I dont know a whole lot about them but they seem like the new thing these days. I have used the smaller board that is in the Hexohm but is only 50w in a mod and built some dna's and a couple Yihi's. But have not a clue about the PWM boards. They seem pretty neat though and would be fun to do. You should watch those Plumes episodes they go into great detail about them and how to build one. Here is a link to somewhere that sells them. They also sell a OKL T-20 mounted to a sled that only needs a few hooks up to complete, its the same board that is in the Hexohm.
If you do build one please post here I would like to follow your progress and how you like it
DIY box mod, vaporizer and, Ecig parts
Tiny PWM
Yes, Tiny PWM is what I've been looking at. Will probably build a test box to see if I like it in use, before I commit to making a custom enclosure. Will post for sure. Thanks.