The only thing is that of course, in smaller tanks, some substances (like bad ones) can have a greater effect. Definitely cycle for awhile, then maybe try CRS first to test it out, since BKK's are so expensive.
My Golden Rule of planted tanks: WWTAD-
"What would Takashi Amano do?"
Im using a 4 gallon currently but its been cycled a long time ago and used to house OEBT.....now CBS + ruby red + WR. The Ruby is now berried. You just have to make sure there aren't swings in parameters or temperature.