Hi euthyphro,
Here's how I would describe a refugium setup:
First off, a refugium is not a stand alone filter but a part of a bigger filter process. Eventually you will want a refugium, sump and protein skimmer. This is arguably the best way to fight toxins in your system. I'm going to assume you understand the nitrate cycle of breaking amonia(fish waste) down to less toxic nitrates. Fish produce both amonia and CO2 as waste products. The amonia breaks down into nitrates which can end up being both toxic to fish and become food for algae. In a refugium you grow algae in a controlled environment outside of your tank to "eat" the nitrates and CO2. The algae in turn also adds O2 to the system through photosynthesis.
Now, the second part to this system is a sump. A sump is nothing more than a water holding tank. It is usually attached to the refugium. For example, my sump/fuge is an old 30 gal tank that I divided into three sections. One section holds my refugium, one section acts as a bubble collector for my water coming from the tank and the third section is my sump. In my sump I have a protein skimmer, my heater, my chiller intake and outlet pipes as well as my return pump. When the water leaves my tank a small amount is directed to my refugium. You usually want a slow flow throught the fuge. The majority of the water goes to the bubble remover and then directly into the sump.
I hope this helps clear it up. I found a nice site about sumps/fuges is:
Melevsreef.com | Acrylic Sumps & Refugiums
Now, about your cansiter filer. A canister filter is alot cheaper and easier to start with. Eventually the material in the canister filter may cause excessive nitrates to be produced, but if you clean it regularly and if you are only housing fish then it should be a great place to start. Remember when you clean it to rinse your bio media in tank water NOT tap water. Tap water contains chlorine and will kill the bacteria that break down amonia. When you finally do move to a sumo you can either remove the canister filter and sell in on Craigslist or you can use it as a place to run charcoal and phospahte removers. I have found it's a convenient place to put all those little bags of chemical removers.
Now, one final thing to throw in. BioBall wet/dry systems are a better version of the canister filter, which in turn is a better version of a HOB bio wheel filter (if you were even considering that). Wet/dry filters provide massive surface area for beneficial bacteria to grow and allow more air to contact the bacteria. The bacteria require air and get some from the water that passes through a canister filter, but will grow faster and better in a wet/dry system. Eventually a wet/dry has the same limitation as a canister filter. It only breaks amonia down to nitrates which is still toxic to fish and corals.
Final thing #2. One option you can do to get the benefit of refugium macro algae is to grow it directly in your tank. Some people actually like it. I have some growing in my nano and it does help remove nitrates from the water which helps water quality and stops other algae from using it to grow.
As I said in my previous note, you should take a few months (8-10) before you think of adding delicate coral. Not only will this give you time to get prepared for it, but itwill give your tank ample time to balance out. Within 2-3 months you could start adding zoos, xenia and shrooms which are hardy. But SPS, LPS and especially clams require very good water and light. You will want some time to learn more about this all before risking a $50 frag of anything in your tank.
HOB Refugium, Cool or Crap? 
I LOVE SUMPS. And refugiums. Get a sump and put the refugium where ever you want. It doesn't have to be in the sump, it can be on the side of the sump or on top of it. Or it could still hang on the tank. One good thing about having a refugium outside of the sump is that you can gain more control of the flow through it and not worry about getting stuff in your sump pumps as much. 
