I'll just throw my opinion in to this mess too. lol
Not many fish for a 5g, to be honest. I ran a 4g with a single clown goby. They dont get more than an inch and a half, and mine was even smaller. The trimmas are awesome btw, I had one and they dont get over an inch so a couple of them would be neat. They perch alot, which is the type of fish you really should be looking at for this small of a tank. More mileage as far as fish. lol If that is a blue spotted goby you are gonna regret putting him in there, I have a purple spotted one that is close to six inches long! Mine might be larger than average but it's just for an example. Mine will also swim here and there but mostly hides in his hidey hole.
No one here want to see you fail, we would rather tell you the honest answers that we came into knowing from our own experiences so you dont waste the money or kill the fish/coral like we all did at one time or another.
If I had that tank I would go heavy on the inverts and coral. A fish tank doesnt always have to have a boatload of fish to be great.