Hey Racehorse - Many of the options folks replied with are devices that are not compatible with EVOD heads.
I've been looking for the same thing. I really like the EVOD's but I'd like to find one with a larger capacity.
I tried the Protanks, but they weren't for me. The new uni tank looks like just a protank with a wider center tube so I think I''ll be doing a pass on it. I haven't tried one yet, but I've been looking at the Vision Victory. It uses the same short or long EVOD heads and it has a 5ml capacity ! I'm thinking these might be a good one to try. I've been using Vision's version of the EVOD, the V.Tox clearomizer and I really like it. Slightly higher capacity, one less air hole so the draw is tighter and EVOD heads are a perfect fit. My only concern with the Vision Victory is that the drip tip is metal. With the cold weather coming here in New England, metal drip tips become less and less attractive to me. Keep us posted on what you try. There must be other EVOD folks out there looking at higher capacity options that will use their stockpile of EVOD heads......