you have 1 hope of breeding L200's in a 3 foot tank and ill leave you to decide what it is....... tank would barley big enough for 2 never mind a group lol
if your after snakeheads in the UK most maidenhead aquatics can get hold of decent specimens if you ask them or you said no DPs but how about one of the other smaller puffers - red eyes red tails red spots? or a couple of south american puffers?