I contacted the seller, he's only willing to sell the head and both manifolds and the carbs as a package.
Makes sense, that way you can be sure it all matches.
I'm not much interested in swapping heads at this point, though I know it could be done over a weekend unless something went horribly wrong. It's tempting, I know I'd be a lot happier with a set of SU's than with the downdraft Hitachi.