So I want to mod Heat Wave to look more like the Dominic Purcell iteration from Legends. Any recommendations?

Well Knights Models makes a 30mm metal figure based on old Dom.

I'd start with parts from an old (Vic Marrow) The Question then add parts from Mr. Freeze and CAREFULLY use a heated exacto knife to cut way The Question's face (so a new one can be attached)

Use the Mr. Freeze Head and use this guy's body, reposition and mod a cool fire-gun

It really does surprise me that they haven't done more for the CW DC universe. Just one little highly exclusive "Arrow and Diggle" set?

CW DC could make for a nice gravity feed set and introduce TV fans to the game.

Wiz Kids other game did a Dice Masters set Green Arrow and the Flash, targeting a lot of characters from the two shows, and the most recent set, Batman includes Rip Hunter. WK is aware of the CW DC Arrow-verse.

Aware of it, sure, but not Clixing it outside of Arrow, Diggle, and the Arrow-Cycle. I'd like to think that the shows have enough of a following that if WizKids were to produce a Heroclix set specifically based on the CW shows, and with four (soon five) of them, there's plenty of material to go off of, they could have a very successful set on their hands with the right marketing.

I know I'd enjoy playing some Team Flash or Legends of Tomorrow teams.