I would, personally, stick with a dwarf or honey gourami unless you are planning to upgrade the tank, and keep in mind that they don't do well with pairs. You can have 2 females, but 1m/1f is usually asking for trouble as the male will harass the female to mate, sometimes to death. Harems are the way to go with gouramis.
Moonlights get too big at 6" to be housed in a 29g with an angel. IMHO, a 29g is a little too small for an angel anyway, but I know many have done fine with it. Pearl gouramis get to about 4" so are kinda borderline for a 29g. Again, IMHO, I would not do it.
I don't see any compatability issues with those fish, just tank size limitations and possible stocking issues with the harem thing for the gouramis.