I have a new concert sized lanikai zebra wood ukulele with 19 frets. I'm not sure if having a slotted head changes anything but the ukulele has a slotted head. The ukulele came with aquila strings but I want to change the strings because I don't think Aquilas go well with zebra wood. I've also heard that worth strings sound more mellow and think that would be my best choice for this ukulele. The problem is that I don't know which set of worths i should buy. Should I buy Worth BM soprano/concert? or would Worth BL soprano/concert be more suited for my ukulele? Or maybe tenor sized worth strings because of the increased fret board? Thanks for your help.