You people are missing the #1 factor behind the decision for a wetsuit.
Drysuits are $texas.
Not only that, but we aren't sailing in 0-5 degrees here. This is for mid-atlantic fall/spring sailing, and winter sailing on lakes. I used a full 3/4 all last years with no issues, and I've got piss-poor circulation.
Wetsuit will work for him just fine. Drysuit is overkill.