Duck Invader 13 is going to give you the best option as far as availability, comfort/room, and hide. They grass up well and hunt great with flapper boards. Most of my friends have them after failing to locate Roy boats.
I always went with rogers breathable insulated waders and liked them. I bought a pair of extremely lightly used Sitkas on here off a member and absolutely love them. I just wear heavier fleece wader pants and alpaca socks in them on the below freezing days and never have an issue.
Another fun tidbit, pictures of me gunning from this boat were published in Ducks Unlimited Magazine in an article by fellow duckboats.net member Larry Metzger.
Bob Fricke Sneakbox For Sale
Boat, trailer, and canvas
Garage kept its entire life
Glass over cedar
Loadrite trailer
Front and rear decoy racks with grass rails
Highlands style box canvas with bonnet top
Hatch cover
Up to date registrations for both boat and trailer
SOLD
This is the last...
You're not going to find plans for a high box, they're a backyard built homemade rig. The general idea of them can be replicated, lower profile boat with flapper boards. There's a lot of mystique around the high boxes primarily because of lack of availability and a certain someone's social...
Another one for the lanyard. Actually saw the band as I put the gun up with a pair of blacks backpedaling at 15 yards. Always a nice surprise.
Five year old bird banded on the Chesapeake Bay, pretty sure the first bird I've killed north of where it was banded.