excellent,
the galaxies and danio's are actually the same family (galaxy rasbora is an incorrect common name for them, the correct common name is celestial pearl danio but both are used regularly) so body shapes etc are v similar, the leopard danio's get a lot bigger than the galaxies. the galaxies in the shop will often look fairly drab in terms of colouring, kind of grey/brownish, once they are settled into your tank they come out in a beautiful purple colour with red fins on which leopard danio's most definatley do not get!!
both ottos and pygmy cories are not suitable for newly cycled tanks, have a look at something like dwarf chain loaches as an alternative.