Ancistrus some panaques (esp. royals) and Chaetastoma would be best. However, in your tanks, Ancistrus and Chaetastoma would be too small, in general plecos and rays dont go well together either. It would also depend on the type of algae you have. Theres no way you can't find some stuff about algae eating plecos, its the most commonly question asked about them lol.
I've said it many times before, only buy a pleco because you want it, they aren't in any way clean up crew, no fish does the work for you. Have you tried everything else to reduce algae, e.g. water quality (reducing nitrates), less light (esp. sunlight) hitting the tank. I get no algae mainly because i keep the water quality so not to promote algae growth and use little light. It is not guaranteed any individual will eat algae also if fed well. Plecos produce nitrates enhancing algae growth if anything. An algae scraper is the number one best solution you'll get.