"Obama would have vetoed ANY plan they presented while he was president." You have no evidence of that because it never happened. Obama was very low in terms of vetoes. It was a Republican Congress so they could have overridden the veto.  They could have wiped Obama's butt with a plan to prove him wrong. Your fallacy: overgeneralization from limited data. 
So this is not the "first real opportunity" for Republicans. They have always had an opportunity. They choked. At least Trump knows how the pharmaceutical companies have bought congress and screwed us (below).
Republicans who vote for Trump and who are also low income will be the ones most hurt with HSA's and tax credits. 
I'll make this prediction: no plan will be affordable unless we control prices. Socialist countries that have done this have lowered prices. Sure, there will be many problems too. Choice is an illusion. There is no choice when one goes bankrupt from medical costs. 
http://ytcropper.com/cropped/gT56c3eb20571c6