Ok, so a "local store in the area" could be anywhere from Sydney, Australia, via Austin, Texas, U.S.A to Luleå in Sweden, or perhaps Rovaniemi in Finland? If you fill in your "Location" in the profile, it would help us help you. [Not that it REALLY matters for this particular question, but for instance someone living in the same area would know what the water is like, and if it's a reasonably big store they would probably know the store and what the commonly stock].
Aside from that, a 30g tank isn't particularly large, so the smaller cichlids would be the ones to aim for. You don't have hard water, so you should probably stay away from African rift lake cichlids [Malawi and Tanganyika Cichlids], although those have a tendency to be very colourfull...
I wrote down a few of the "nicer" small cichlids in this thread
What's pretty and what's not is a very personal opinion thing, so I can suggest half a dozen fish to you, that I think look super-nice, but you think they are not. I can't tell what you like and what you don't.
A shop that specializes in salt-water fish is probably not a bad place to buy fish, better than some of the super-chain places, where no-one knows anything, and just sell common species that are easy to sell.
But in the end, choosing what fish to have in a tank is a bit like choosing curtains for the house. Some person will like dark brown plain ones, another the white ones with big flowers, a third person will choose plain white ones, a fourth person may hang plastic bin-liners across the window to make it dark, no matter what the rest of the world thinks about it.
However, you want to consider the maximum size of the fish, consider it's natural habitat and it's compatibility with your water [the shop, if it's using the same water supply as you, would be able to tell you the pH, by the way], and temperature. You also want to consider the different fish in the tank, and make sure they are compatible with each other. The last thing you want is to buy a new fish to your already set up tank and find the next morning that you have only ONE live fish in the tank.
Also, when setting up the tank, don't stock it full in one go. Get a few hardy fish to start out with, and then add more fish once it's established after some 6-8 weeks [it's a good idea to get a test-kit, to test the water with, but most shops will do a test for you. It's just a pain to get water out of a tank, drive to the shop, test it, and drive back home again.]