Hello Steve,
Honestly to me it sounds to me like you've done a lot of research and I personally think you are freakin yourself out. If you keep up on water changes and keeping the tank clean you'll be fine. Usually water quality is the cause to most problems. That tank imo would probably only be good for 3 or 4 fish... I def think you can be successful with that set up if you can put some time into the maintenance once a week. Good luck and hopefully soon we will see some pics of a tank with some good lookin fish.