erm, as a grow out tank? Acarichthys heckelli, though slow growing, grows to 12 inches. The turquoise sev to about 9 inches ... neither would have much room to turn around. And would probably claim the entire tank. Plus sev's would most likely (but not always) treat your plants as a self serve salad bar.
The South american leaf fish plus a dwarf pike (not compressiceps!!!) would work well with the BN pleco though. (I keep dwarf pikes in similiar sized tanks).