Need help / guidance

Hi! we are looking to open an online jewelry store that will focus on engraved rings, bracelets and necklaces. I want to know what are the best materials to purchase for a non tarnish daily use jewelry that you can sweat, shower and do everything with. I'm stuck between a stainless steel gold plated vs gold filled. if you have any suppliers or locations where I can buy in bulk please share! Thank you for your help!