Off the shelf an apc15x7 works well. My favorite funfly prop for my 60SuDoKhoi w. a YS91AC is a Zinger16x6 that I heavily modified. I pointed the tips, a straight line from tip TE to 2" in on LE, then reshape airfoil. Basically the whole prop is worked over, but with a little $60.00 disc and belt sander from Harbor Freight and with frequent balancing of the prop during the procedure, it only takes about 15 min. I would also like to try a PowerPoint16x6. I read that a Zinger16x6 develops the must thrust on a YS120, sounds good for my YS120NS and Jerry's Spoiler.
DKjens