I'm still a FNG, but what I have gleaned from my research is that I believe you're going to be EXTREMELY limited on what you could add, fish-wise to your 10g. Some might suggest that you're maxed already.
A few other things I've learned (May not be pertinent to your situation) . . .
- Cycle first and foremost, wait until it's complete, then start adding livestock.
- Bigger is better, particularly tank size. Larger quanties of water are more stable and easier to maintain. We were originally going to go 55g, almost settled on 75g, now there's an empty 90g in my wife's office waiting for the rest of our gear.
- Test your water with a quality test kit.
- Inverts/corals, etc require very specific lighting. Not just a lot of light, but of the correct color temperature, spectrum range, and strength.
- 1lb LR per gallon a good starting point, or even more.
- Water changes a necessity.
- Go slow.
- Plan your livestock purchases carefully, or there may be an aquatic WWIII in your tank, and your prized animals may suddenly start disappearing and only reappear as fish-doo-doo on the bottom of your tank.
- LR needs to be cured, lest you risk an ammonia spike and restarting a cycle.
- Damsels are mean little buggers.
- Tangs need a big tank . . . some say 55g minimum, some say 75g minimum, others 100g or above.