Bed rack fabrication question

Hi. New here so first of all thanks for all the knowledge I've gained by reading all your posts these last two years. Here's my question. I' fabricating a bed rack. Got the rail brackets fabricated and ready for the rack itself. My question is materials based. Should I fabricate the rack with 100 wall steel or 1/8" wall? Was thinking 100 wall would be lighter...But as the years pass will it be enough to withstand the rigors of use? Canoe strapping, and steel hauling.
I'l be mig welding it with .35 wire onto 3/16 angle iron brackets. Thanks in advance.

 

Welcome aboard. There are a lot of guys on this site who would be glad to offer advice. Always good to see a man building his toys. here's one to ya.