I'm not disputing that the ACA is not working for everyone nor as to its sustainability- despite the fact that its tax credits are the only reason I am able to afford insurance here. 
Two possible options- the senate tweaks the bill to make the subsidies more generous across a wider income range, and pegs the subsidies to region and income instead of age, and/or expands Medicare eligibility. In which case I'm not sure how it differs much from the ACA in principle, which makes it a non-starter with conservatives. The other option is a universal healthcare system run alongside supplementary private industry insurance options, which in addition to covering everyone,  is the only option that has any chance of controlling and decreasing skyrocketing healthcare costs. This option, too, is a non starter with many conservatives. 
What would you propose?