"I have seen and played a Baratone uke with 4 heavy gauge flat wound guitar strings fitted E A D G ..sounded ok with a uke band..if amplified with the treble cut .. it sounds even better."
THAT sounds insane unless you have a reinforced neck. Did you get a chance to examine the instrument? Hmmm, now that I think about it, guitar gauged flat wounds on a 20" scale might be ok. LOOK OUT! Here comes another case of UMS (Ukulele Modification Syndrome)!