A few years ago I had a custom boat built literally from the ground up. I went pretty top end on everything including the sew work. I actually hired a team that had a hot rod show on discovery channel at the time to do the seats thinking I would end up with the pedigree stamp of absolute perfection… well… they rolled that boat around the shop for a month making sure it was never in view during filming and when it was time to pick it up I thought it was a joke, the quality was horrible. Don’t think you need to pay top dollar to get top quality.
Shaun is the go to guy when ego is on the table. Expect higher rates and longer deliver times, but you do get to say sewing by Shaun.
Tony is amazing and has always had fair pricing.
Sew a long is unbeatable but good luck getting Justin to Powell - he is busy as ever with work in SLC and chances are zero he will do your work, he has an awesome team now.
There was one other guy named Eric who broke away from Shaun many years ago but last I heard his fingers locked up on him - he was over by the ice plant - amazing tippy top work at good pricing. 928-660-9274
Regarding the aluminum frame, about 10 -15 years ago those frames were scattered all over the storage yards as most people removed them to upgrade to proper columns and framework and hard tops. There is no way I would replace the canvas and original tube frame, consider taking this opportunity to upgrade to hardtop with legit square tube design with baseplate mounting. A call to lake Powell marine should get you started.
Most sew teams resupply from a group in Denver called TriVantage, a great place to educate yourself.
If you are in SLC you can get all your aluminum from Affiliated metals, Page steel has a good selection too.