Nope that'd be way overstocked, the sevs alone need something
towards 100g (before I get the usual lynching off other members about how they only get to 4" and they keep theirs in a 20g with an oscar or something lol), then the JD and everything else on top - you'd be looking at at least 135g I'd think.
55g stocking ideas:
http
/www.cichlid-forum.com/articles/cookie_cutter_55g.php
Scroll down to Central American, according to them you can have a pair of JDs but that'd be it. They also recommend another type of thoricthys (same family as firemouths) so you might get away with a pair of firemouths in there. But it'd have to be one or the other - not both. If you went for calmer cichlids, you could have some other fish in there. One thing I should say though is that they recommend a gold nugget plec in with cichlids in a 55g, but in reality gold nuggets can get up to 16" so that bit at least is a load of crap lol.