trianthlon suits are often slick on the outside ( meaning, slick neoprene ) NOT resistant at all !
i would say, if you are in the right thikness for your water temp of course, the right suit is the one that suits you !
i mean, if you feel opressed in it, if you cant breathe right in it, or if the fisrt thing you want to do if get out of it once done kiting, then, it's not the right one !
i could spend the day in mine, it's comfy, follows my mooves, and does not restraing my bloodflow on hands or feets ( it might not be as tight as the sales man wanted me to get it, but i feel good in it, that's the main point )
i woudl say, dont use ols suits and specially not old diving suit ( as they dont stretch good and sometimes dont stretch in all directions ). new ones are WAY more elastic.
as for durability, well, mine has knee pads made out of thick cloth, nice when you knee on the beach to prepare your gear. and a front zip entry cross chest that is 100 percent water tight , PITA to getin and out but, comfy and no zip on the back to make pressure points with the harness ( like some surf suits will do )
last thing, board shorts : yes, they are for the look, but ( i ride in a seat so, look, outch ) they are to protect your suit, better tear a 40 dollas short then a 300 dollars suit. and, they have pockets !!