I use .065 wall 1" stainless for making bimini
frames. I am considering the same project
. Am thinking I would have to tighten up centers of stanchions. With the cable they're typically 6' apart. The hard rails I see are 40" or so on center. If you check out miamicorp.com or manarthirsch.com they both have tubing up to 1.25" in 305 and 316. I've been looking for a reasonable price
for "T" fittings. I pay about $3 for stainless bimini
fittings but none of my suppliers carry the rail fittings.
The rail fittings would negate the need for onsite welding and the associated fees