Clowns, chromis, damsels, some gobies, dwarf fuzzy lions if you have the tank space, some wrasses, some blennies, and other common sw
fish you hear of like that.
I really wouldn't worry about telling him about the tank size though. I really don't get it. On other posts people want a 10 gallon, everyone suggests a 29. Well in this case your suggesting abigger tank than a 29 lol. IMHO
a 29 is better than a 10 or osmething smaller than that in starting out becuse it saves you the initial 6 month upgrade most poeple go through.
But yes I do get why the bigger tank was brought up and it is a good point.