I have a nuvo 30 and I'll tell you what I did. 1.5 bags of caribisea pink. I didn't go with reef cleaners because they don't overnight to my area for some reason. I used liveaquira. I love LOVE the ceriths. I got quite a few of those. I also love the spiny star astraeas. They have been quite hardy. Nerites have been pretty good as well. I prefer the smaller snails in my cube because I have a huge, tight aquascape and the larger snails just don't get in there and do work. They stay on the walls.
Load up on certihs, nerites and grab a few bigger snails maybe around 5. I'd also throw in 5-10 hermits. I'd recommend the smaller ones not the large ones like the scarlet reef hermit, although I do have one of those. You will have some that don't make it very long so take that into account.
Again, this is just my opinion but I am cycling a 24g cube at my office now and I plan to do the same thing.