Tough call. Not being JUST the fanboi that I maybe have come to be around here, but seriously??? I'd dump the cabs and simply aim to get a FL-G12K100 4x12 Diezel cab and get the Hagen. I've got this set up and it's up there - it's holy graile material. There's little (no??) need for anything else.
I've run the course of a lot of gear - not saying my tastes are your tastes, that's not the point. But if you're already sold on the Hagen, that means you love it and know all about it. So why mess around?? Just get in there, cut yer losses, get on board for both and don't look back. Seriously. The Hagen won't sound as good through anything other than a Diezel cab (and even if it did, you'd always be second guessing it, wouldn't you???) and if you've got a Diezel cab, well whoop-dee-doo, so you've got the wheels but no engine