The main reason for line in wreck diving is for wreck penetration to be your "bread crumbs" to the exit in case of emergency (light goes off and backup too, sudden drop of visibility caused by reckless divers or other incidents etc). In that case medium to low low end line is enough as you’ll reel it back when exiting.
It has to be somewhat resistant to cuts (rusty wall edges etc.), but since it will not be used as fixed guide line or for lifting/salvaging I doubt you’d need tech grade lines. When it comes to reels it’s simply personal preference, but I found it important to have one that reels back in easily.