Scuba diving and surfing wetsuits are usually made of neoprene, but the difference between them is generally style and cuts. If you are looking at a shorty or full suit up to a 4/3mm thickness, chances are that each suit can be used for surf or scuba with no problems. The thicker scuba wetsuits have more air bubbles in the neoprene which acts to keep the suit from compressing at depth, and thus losing warmth.
Thicker surf suits have less bubbles in the neoprene so if used for Scuba, once the diver reaches about 33 feet or even 60 feet the atmospheric pressure will compress the suit thus making it less warm.
So, the answer is, shorties and full suits up to about 4/3mm thick are pretty much interchangeable, as long as you are happy with the style and cut of the suit.