Go one piece.If you are buying it for saftey as well as warmth then the one piece is the way to go.There is a reason why the Coast Guard wear one piece suits.If you look around you can still find some Natilus suits for sale.I think that Fishing world still carries them.I have Natilus 1000 series that I bought for 299.00 and its a great suit.It also has the suspenders wich is a great feature.Just shop around.