Are you looking for display plants, or just functional ones, or a bit of both.
Cheato is very good at removeing nutrients and its stable, but not the the most attractive, although I like it and it does provide a spectacular habitat for little creatures.
Gracilaria is a nice looking plant which is fairly stable, it can be difficult to keep.
Codium is very nice , but I dont have any experience with it yet.
Lets figure out what it is you're looking for and then we can help more. The list could be huge try checking out some of the vendors to see whats available and maybe ask more questions from there.