I wouldn't suggest plecos or algae eaters for algae. A lot of plecos will get lazy as they get older or only eat algea when they're really hungry.
I'd say something like Panda Garra. They are awesome patterned fish and absolutely go CRAZY on algae in tanks. Just keep in mind that they like to school, so about 5 is a good number for them. They stay at about 2.5 inches if memory serves me right.
Ottos would do nicely, too, though.