[Zoe]

Is there a reason you want to move the gold out of the 75 gallon tank? Do you have other angels in the 75? Angelfish aren't really schoolers per se, but they do enjoy being in groups.
I think you could put your angel in the 29, but I don't think you'd have room for other angels, namely because if you have only 2 or 3 angels (2 being the most I'd recommend for a 29 gal), you may see some aggression. If you put the gold in the 29 gallon, you could have him being the only angel, along with a school of tetras (neons or glowlights - small tetras, not larger ones) or rasboras. Or some small rainbows, like furcata forktails. Or, if you fancy something small with a bigger attitude, some scarlet badis or blue badis (not that they're aggressive or anything; I just find they're more individual than tetras and rasboras).
Either that, or you could try setting up your golden with a mate? You might want to try getting them to hook up in the 75 first, but then you could move the pair into the 29. But in that case, you probably wouldn't want to get any other fish, as the pair will probably want to use the entire tank to themselves when they're spawning.

Just a thought, and I might be anthropomorphising here, but I'd be worried maybe a tad about moving a fish from a 75 gallon tank to a tank half that size.