What is the exact length and width of the tank though? Gallons is important, but things like the actual length and width of the tank is especially important as pleco's are primarily bottom dwelling fish and you can have two tanks both of which are over 60gals but are very different in their actual dimensions etc.
Here is a link with 30 plecos under 8inches if you are looking for smaller plecos since some grow giant in size;
http/www.fishforums.net/index.php?showtopic=132656
Planetcatfish.com is also a very valuable site for doing research on plecs and other catfish (lists hundreds of types of catfish and often has many pics and much info on them too);
http/www.planetcatfish.com/catelog/index.php
Personally, if you are looking for a clean up crew for algae i would go for a group of 4-6 or more oto's as although they are small catfish, they make very efficient algae eaters.
For pleco's in general, if you can get hold of one of them, these make very stunning pleco's in particular to own;
Titanicus pleco (max size: 11-12inches long);
http/www.planetcatfish.com/catelog/speci...?species_id=234
Para pleco (max size 6inches long, despite the info in the link);
http/www.planetcatfish.com/catelog/speci...?species_id=195
King tiger/network pleco (max size 4-5inches long);
http/www.planetcatfish.com/catelog/speci...?species_id=174
Starry nigh bristlenose (max size: 3-4inches long);
http/www.planetcatfish.com/catelog/speci...?species_id=442
Most of the above pleco's are pretty hard to come by, so if you want something less uncommon/rare, i would personally go for a trio of clown/ringlet plecos if you get some mopani/driftwood/bogwood in the tank as these make very attractive small growing plecos which aren't hard to come by;
http/www.planetcatfish.com/catelog/speci...?species_id=734
I'm just scratching at the surface here, there are tons of gorgeous plecos and other catfish out there, planetcatfish is a good site for researching such fish as i said- i would go for oto's though if you just want some good algae eaters
.