i have a kilt in 10oz but then again i live in southern Nevada where the temps go to 120fh in the summers i would do a summer casual kilt and maybe a vest or how about a nice hat one thing about lighter fabrics it is true they don't swing or hang like the 16oz but they take a pleating well and are easier to sew in the long run just my opinion and with heavy interfacing and the right wast binding it will hold just the same up top were lighter fabric wait could be a problem with stretching or showing under lines that sort of thing but i'm no expert have you asked Barbra T or one of the other kilt makers what they think?
Paul