I have zebras and would recommend otos (otocinclus catfish) as they are awesome little fish, stay small, and do wonders on the algae! Plus, they are peaceful and get along with the danios well (but otos are social and prefer to be in pairs). But I don't know how they would work with the snails as I've never dealt with snails before. How many danios & white clouds do you have? You also want to ensure you don't overstock your tank. (I have a 10 gal, too, and my 6 danios put me at max capacity!)
If you do decide to go the oto route, research them first by reading their species-specific thread on this forum, and go to
www.otocinclus.com for more info.
Good luck!

Sharon