As I HATE waders with a passion, I wet wade exclusively any time the air temps hit the 50’s which means from April through November. All I use is my regular wading boot, a pair of heavy wool socks and a pair of 3.5 mm Neoprene “Guard Socks”
WITH the built in gravel cuff like those sold by Simms and Patagonia.
Wool sock over bare foot, guard socks over wool socks, shoes over all. You will get the same fit as you have when you wear waders because the guard socks are the same thickness as the Neoprene bootees on waders and you will have the protection and grip of your regular wading shoe.
BTW - Regular Neoprene wading “socks” are usually thinner than the Neoprene found on wader bottoms which is why I don’t use them in lieu of the thicker Neoprene guard socks
with built in gravel guards.
(NOTE - the Orvis version of a Neoprene guard sock is NOT as thick as the Simms or Patagonia or a regular wader bootee.)
If you need to tweak the fit, get a thinner or heavier wool sock. I like wool as the base layer because it feels more comfortable and less slippery over my foot when wet and adds some cushioning, although I am sure some folks put a bare foot into their guard socks or wader bootees.
The only thing that makes this combo better is a pair of zip-off lightweight nylon fishing pants tucked INTO the wool socks to protect your legs from critters & poison ivy. They WON’T help with nettle or thorns but are better than just shorts, especially if you have to walk through tall deer tick infested grass or brush on the way to the stream. Once there, you can zip-off the bottoms if you wish and fish in shorts. They are also comfortable, dry fast and add zero bulk.
In regards to wet wading specific footwear options; to beat an already dead horse, sandals are for optimists in sandy-bottomed places. You will regret owning them for wading in any rocky or urban stream.
Also, many if not all of the lightweight wading “shoes” I have tried have a completely different fit than a full sized shoe from the same manufacturer with bottoms that are a major compromise over what I want in a regular wading boot. In other words, sometimes they are way too tight with the wool sock/guard sock combo, with hardly if no felt options, limited choices that will accept studs and lousy protection on the sides and top of the shoe.
One piece of advice if you go the guard sock route, do your best to try them on as the sizing is suspect. Sadly, Simms completely redesigned their original product a few years ago. For me it is too narrow at the top and extremely difficult to get over my rather average 10.5 foot and a wool sock. Once on, it is excessively tight around my lower leg above the ankle. The Patagonia version has the same issues. Going to the next largest size doesn’t solve the leg-fit problem either and leaves me with a sloppy fit over my foot area.
The good news is Simms has a new version referred to as the "Guide Guard Sock” (that I haven't tried yet) which may be similar to the original in regards to fit. Right now, I am still using a couple of old, nearly shot first generation Simms Guard Socks while I wait to find something I like as much.
FYI:
Simms Guard Socks - Redesigned Version
Simms Guide Guard Socks - New Product
Patagonia Neoprene Socks with Gravel Guard
Good luck!