Unless you already have the 10 gal tank, get something larger. You are really limited in the number and type of fish you can easily put in a 10 gal tank. Mollies need larger tanks and so do dwarf gourami (not to mention the health issues they are prone to).
The only catfish that could fit in a 10 gal are the pygmy corydoras and they are sensitive fish. That just seems to be the trend with fish that are small enough for a 10 gal: sensitive. Your choices greatly increase with even a 20 gallon tank.
Honestly I'd recommend getting rid of the 10 gal and upgrading to something larger BEFORE you get the fish. A lot of things can happen before you that planned larger tank comes to fruition, and it's the fish that will end up suffering. A 29 gal is a great size for a first community. It's large enough to have more than just one or two species of fish in there.
A 10 gallon can be a nice little environment if you care for it properly and have a good mix of fish. Like 3 Kulii Loaches (and maybe a DG if you keep up pwc), 5 female Betta, 16 Neons, 1 male Betta or DG with inverts (like shrimp and snails), 1 Betta and 4 Cory Cats, and so on. The best way to figure out what will work best in your tank is to find out the pH and hardness of your water.
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I'm going to disagree with you here on the kuhli loaches. Three is the absolute MINIMUM that should be kept together; just like keeping bettas in 1 gal bowls it can work, but it's not best for the fish in the long-term. Same with the cory cats; that's the min that should be together. When you keep a fish on the cusp of its comfort zone, you will have problems in the long run. I would also like to say that after having kuhlis and watching their activity level for 5 years, I'd say a 10 gal is too cramped for all but a few species of Pangio spp
EDIT: It may also interest you to know that the mother site of BF has tropical fish profiles that will tell you about the needs of specific fish. You can find them here: http://www.tropicalfishkeeping.com/profiles/