Is that starlight bristlenose the kind that gets to 8"? I can't remember L numbers but, if it is, you should consider how much waste it will be producing once full grown and be very careful with your stocking. Anyway, as you have 2 panda cories in there, you are best off avoiding these cichlids altogether. Particularly with pandas which are quite fragile cories, the group they are in is much too small to discourage attacks - which are very likely to occur if you have a breeding pair of cichlids defending the lower levels in your tank. Otherwise, all of them could work (would lean towards bolivians myself - kribs are a little more aggressive - also happen to be african - and the cockattoos are apistos so should be kept as a trio rather than as a pair so, obviously, they take up more room). The bolivians are also the smallest out of those 3 and hardier than the cockatoos (though kribs are hardy as well). The betta could also pose a problem though, being a plakat, he is less likely to get nipped by a breeding pair of cichlids. I would probably be more concerned about him and the cichlids not getting along because both are territorial and 22 gallons isn't all that much room.
edit: Also watch that plakat doesn't turn on your honeys. You've probably heard this a million times before - bettas and gouramies don't mix. One day they'll be best friends - the next they'll all be dead except for one tatty survivor.
