Not a boot, but I'm a big fan of the Brookie Knee-high neoprene socks.
I wear either a liner sock under them alone, of if water is particularly cold, and thin Merino wool sock over the liner.
They run full size, but in my opinion run big.
I wear a 10 1/2 EE shoe, but use the size 10 Brookies.
They come up to knee and have a cinch strap to secure.
Depending on the volume/fit of your warm weather shoes, they might fit them. I buy discontinued Teva style low cut water shoes and will buy a 11-11 1/2 to accommodate the bulk.
I seal the exterior seams with seam sealer to keep the abrasion of the stitching at a minimum.
I like the fact that if the day heats up, you can roll them down like fireman's boots to air your lower leg/feet if needed.
Very flexible, so kneeling is comfortable.
Just something a little different to consider if your of the mind ;)