[Regisfofo]

There are a lot info to gather on that subject on the live subforum.
I worked extensively this year on a similar setup with reaper.
Short answer : explore sws live config fonction.
Then if it does not do what you want, explore lbx stripper script (I think it can do anything....).

For hardware you should consider nektar's pacer. It is very flexible, has color led. With a few tricks, I had mine to blink a led for showing tempo.

All the best

Edit : solution from dodzy above works fine for very simple sets, but won't work properly with delay or reverb plugins....