I don’t think you’ll find a longer-travel full-sus 29er which will work well in sizes below a medium, to be honest. There’s just too much to fit in! How tall are you?
If I were you I’d forget about wheel sizes and find a bike which has the right capabilities, and fits you. Whatever size wheels it has should surely be secondary?
All that said, a Mondraker Crafty comes in a small, all sizes seems to have loads of standover clearance, and looks like a cracking bike.
Or, if anyone has enough experience of 29ers to crack the geometry for small size/long travel, it’d be Niner. Maybe take a look at their WFO 9?