You're dreaming if you think those groups would vote to destroy their jobs (or severely curtail their compensation). Personally I think a single payer is the only way we cut costs significantly, however I realize there are those opposed and they appear to weild a pretty big stick. For all we know, Roberts saved the law to protect big corporations, and chamber of commerce took no position on the litigation. Insurance Cos. can certainly use their influence and they have shown that they will, thus your "simple" solution is not so simple.
I'm sure you have seen what Medicare does to hospital and Doctor's fees-you think those groups would support a single payer system? Hardly and then throw in nurses and other workers and you have a pretty large voting block.
Good luck getting such a system past either of those groups.
There was quite a push from the "liberals" and the larger push to get a bill won out-such is the system we have of compromises sometimes necessary. There will be talk of improving the bill and it may be forced if there are not enough reductions in overall healthcare costs. May take years or lifetimes, but in the meantime a lot of new folks will be covered-we'll see about those reductions in costs!?
