Keep it simple. It requires the very basic elements of your main aquarium: a filter, some basic lighting, and a heater. An integrated aquarium system like the Eclipse tanks only require the addition of the heater. I think I saw a nice 10 gallon setup that had everything at Petco for $50 bucks or so and I saw a cheap Iron stand at Adam's. An instant QT tank for less than $100 is a super cheap insurance policy that's for sure.
No substrate or live rock but some type of shelter is needed to provide a sense of security to minimize stress on your fish. Get some larger PVC fittings for them to hang out in during their stay.
To set up the QT tank:
Keep an extra filter like a sponge filter, in your main tank (sump), so you don't have to keep the quarantine tank set up all the time.
If you don't keep the tank running, use old tank water to fill the tank. So: old tank water + established filter = instant established tank.
You can use Amquel or Prime when medicating the tank in case the biological filter bacteria are sensitive to the medication. Sick fish are especially susceptible to ammonia.
Do small, frequent water changes (every other day unless you are medicating fequently in the QT then wouldn't hurt to do a small water change daily actually).
If possible, quarantine all of your new fish for three weeks. At the bare minimum, they are already stressed from all the shipping and this way they will be healthy when introduced to your main tank and if they do get bullied a bit they won't stress to death. At worst you just caught an unhealthy fish and treated it before the reast of your livestock get the same disease.
Hope that helps!
