"I’m getting married in Vegas in August. We have decided to not go the usual formality route. I’m planning to wear a tan cotton 2B poplin suit and brown shoes (perhaps G&G Astaires if they get my October order to me).
A couple of questions: Would a contrasting collar, say blue with white collar be too “business like”? Should I do French cuff and links /bars? Regular tie or bow tie? I just want to look nice for warm weather, without wearing screaming white or standing there in wrinkled linen."
You should have your Astaires this month, or so Dean Girling assures me. To complement them, I like bow ties in summer. Navy with white mini-dots looks good, especially with a light blue shirt with a white contrast collar, white french cuffs and some silk knots.
And remember a white linen pocket square!