Neoprene is a wonderful choice for long term wear as it does not deteriorate from body oils. I have had a neoprene sleepsack for many years and it still is a slaves nightmare! LOL - A collar will work well.

Dont know about collar but my old owner had me wear a wetsuit and cath and piss recycling tube for over 2 years. Dont know about you but still get off on the rubber feel against my skin I got it bad as of last count I own over 50 surfer type oneill, rip curl, quick silver surfer suits full with back zip. Its amazing how many places you can wear a full no hood or gloves under your clothes and no one notices or at least in my case didnt say anything. All I know is wetsuits make good pajamas and weekend wear would love to have it perm glued to my skinany ideas slave allan
ps looking for a rubber ltr in baltimore area 410-370-5989