All I know is that the thread itself is a spun synthetic fiber with a hollow core therefore it has an insulating factor that lycra does not. Scuba.com and scubatoys.com have several examples of each. Try on some at your local LDS's. These types of suits are more flexible and stock sizes seem to fit easier than the stock sizes of 7mm wetsuits.
After years in the tropics, I now dive in SoCal. I used to use a lycra skin to shimmy in & out of my 7mm suit but it added no warmth. I switched to a polyolefin skin and was surprised at the difference it made.
If you plan to dive in NJ just go for the drysuit from the beginning. Check out local dive sites and watch what exposure protection most local divers own/wear (other than newbie OW classes in rental gear).
I wish I could go drysuit.....but we all know that drysuits are A LOT more expensive than a 7mm wetsuit.
I'll try to talk to my LDS, about what they suggest, but I do know that they don't carry any dive skins.