I have a Combi-Plan and use it as a daylight tank. It's actually not as bad as people make it out to be to drain--it takes a while, yes, but I've never actually gotten unevenness on my negatives, and I'm shooting TMX which is hypersensitive to processing errors. The fact that I tend to use highly dilute developers for extended periods of time also helps the drain time--I'd be much more uneasy about it (and consider a dip & dunk system) if I was only developing for five minutes or so.

Others have shown you that B&H sells additional tanks.