I fail to see the problem. I often run multiple web browsers simultaneously. It ain't no big thing. If I can run Firefox and Safari simultaneously on a single Desktop, then certainly you can run them on two. Just do it.
It might be useful for you to explain exactly what you want to accomplish by running your web browsers in separate environments. I think that you will find that you are trying remedy a non-existent problem and unnecessarily complicating your life as a result.