I would go with a 20 gallon tank to help keep things more stable and allow for some extra space for some of the larger species.
You would need
Tank, Filter [Hang on back, I suggest a AC30 or higher],Quality heater [i set on a timer so it cannot fail to bad on me. if you have a controller that would be best] Large PVC pieces for the fish to hide in, fake coral would work or barnacles as well. Small powerhead would be optional depending on the size tank you choose..
Some people argue against the use of a light but im using a small LED from rio sun during the day. A good cover is good as well, Will help in reducing evaporation and especially if a fish trys to carpet surf.
You do not need live rock in a QT tank, Some people use rocks and some people do not. I currently have some in mine but i will be removing it.
Obviously Copper treatments would ruin the rock and I have read that hyposalinity can put the beneficial bacteria in a suspension like state and of course kill any rock dwelling creatures that could potentially spike your water quality and do more harm than good.
Water changes should be performed as needed. generally every 2-3 days. Testing Ammonia and PH twice a day.