First of all WELCOME to the SWF board danielfish...
Next...there are a few Lions that may be OK in a 29-30 gallon
The Dwarfs, as Lionfish12 mentioned, Fu Man Chu and possibly Antennata...
Check out this thread for some pics of a few https://www.saltwaterfish.com/vb/show...hreadid=137610
and use the "search" feature at the bottom of the forum page for more information...
u can also fit a dwarf fuzzy or dwarf zebra
The smallest is Fu manchu at 4" adult size. the largest is the Antennatta at 8" ault siz and thje other two are both 7". note that this is the average adult size and yur lion may not actually get this big.
I just put an A. Lion in my 30FOWLR. She's doing quite well and will be the only inhabitant of the tank, besides a very nervous blue damsel!! I think keeping the bioload down will give you greater sucess in a smaller tank. Good luck:cheer: