I had the similar dilemma a few months ago as to what FS to have along with owning a Soul and for the same purposes as you.
Bought a 26″ Bandit frame and run 150mm Pike up front. There might be some deals left for the Bandit at 26″ and you could build it up with bits and bobs from here for under 2k.
650b might be all the rage…but I’m sticking with 26″.