Originally Posted by
louky
Can I get away with leaving these friction shifters in place?
Sure.
Originally Posted by
louky
After I change the bars, can I just use some regular inexpensive brake levers like would be on a MB?
Yep. You need short-pull levers, which all of them from this era will be. You probably have a set or two laying around.
Originally Posted by
louky
Since these bikes are 2 x 5's is there an option for using those combination brake and shifter sets? TIA!
Not really. I'm not aware of any indexed shifting options for 2x5 that will fit on flat bars, and almost certainly nothing stem-mounted. For what you're trying to do, keeping those existing friction shifters are the best bet.