I don't want to be a party pooper but having a QT is very important since at least 75% of the time the fish you buy WILL have something wrong with them.
Now that you put possibly sick fish in your new tank, chances are the tank is infected and it will infect any fish you add even if they are healthy.
Some people use the hit and miss method but mostly they are at the LFS every couple of weeks looking for new fish to replace the dead ones.
Your best bet is to get a 10 gallon tank, leave it bare bottom, cycle it and the next fish you get should be QTed for at least 3-4 weeks.
