I'll leave the mount choice to others,except to say that the various Hyde mounts seem to be the most popular,followed by the generic Ys one, and the ZN one.
Re the stab tube,it's more or less standard practice,if you need to have the stab removable, to coat a loose inner with medium or even thick cyano, LET/MAKE IT SET THOROUGHLY, then when it's just too tight, lightly sand to fit.