There are many cichlids that would work, and there is just about enough height for silver dollars. I'd up the numbers of clown loach to 6, as IMO the tank is a good enough size for them

You will need at least 6 dollars in a group, so with dollars and clown loach and the barbs, you would be fully stocked.
One word of warning though.... It looks from here that the tank was not cycled with liquid ammonia, and no mature filter media was added. If this is the case, you are probibly undergoing a fish-in cycle, which can be dangerous to fish... Do you have a water testing kit? If not, you need to get one realy, as when issues occur, water stats will be the first thing we ask for. We usualy test ammonia, nitrite, nitrate and pH. Liquid based test kits are the most accurate and strips aren't even worth bothering with IMO.
In a new tank that was not cycled using ammonia, you get an ammonia spike after adding fish, that will often start to kill off fish once it has had a few days to build up. After the ammonia spike, you will get a nitrite spike that is also toxic to fish. Finaly, nitrate will start to raise. Nitrate is not as toxic as ammonia and nitrite and gets removed in your weekly waterchange, but ammonia and nitrite will kill quite quickly if presant, and need to be kept below 0.25. We do this via waterchanges, as we do with nitrate. If the levels are above 0.25, we waterchange to remove some of the toxic waste. You will idealy be testing at least daily untill the cycle (the process of the filter maturing to deal with ammonia and nitrite) is complete. This usualy takes arround 4 weeks, but can be longer or shorter

Just a word of advanced warning.
I deffinately would not add any more fish at this point, untill waterstats are known and posted, so that we can advise on when it is safe to get more fish. Adding more fish before the cycle completes will increase the levels of ammonia and/or nitrite, increasing also the chance of killing off the fish in the tank
All the best
Rabbut