Earlier quoted context omitted.
About fifteen years ago I was working on a venture to make an open-content journal publishing system. It didn't pan out for various reasons, but the general argument we were making this. Here are various services, and who (or what) handles them: - Peer review and top-level decision-making. This is handled entirely by the editorial board. - Typesetting. We have a free system for this: it's called LaTeX. - Copy-editing…
Thinking in terms of for-profit sounds like the wrong way to do it. You need to setup a 503c Foundation, much like the WMF. Edit: it occurs to me that the Wikimedia Foundation is actually in the best position to do this! If you tried this before and still have the old infrastructure or business plan, have you considered approaching the WMF Board?
I abandoned the project well before the infrastructure was ready for prime time: the tenure clock beckoned.