14 gauge steel is 25% thicker than the 16 gauge stuff. You can easily use the 14 gauge and probably never know the difference in the end product. Any drilled holes will take 25% longer to drill (and there are a lot of rivet holes to drill, and all cutting (200+ cuts reported) will take longer too. It really comes down to your choice IMO.
_________________
Chuck.
“Any suspension will work if you don’t let it.” - Colin Chapman
Visit my ongoing MGB Rustoration log:
over HEREOr my Wankel powered Locost log :
over HEREAnd don't forget my Cushman Truckster resto Locostusa.com/forums/viewtopic.php?f=36&t=17766