I agree with what Reeffreak and Yote say so far. Don't skimp on a skimmer, it's one of the most important pieces of equipment you will buy. If you find one that you think is good, post your thoughts on here and we'll you what we think about it. I agree that the Aqua C brand is one of the best...
Some people say that a return pump will chop up pods from the refugium, but I doubt this is the case. After all, running a refugium works for so many people to provide live food to their tank (mine included).
I also second Yote's suggestion to make sure you get a mandarin that eats frozen food. These fish are difficult to keep and often starve to death, especially in new tanks, because they are such picky eaters. If you can find one that will eat frozen mysis you will be a lot better off. Keep in mind that even if you see pods in your tank, the mandarin will quickly eat these and then will run out of food (which is why a refugium is important).
A refugium will work better with a light. It doesn't have to be high-powered or anything. You usually keep macroalgae such as caulerpa or chaetomorpha in the refugium, which provides habitat for the pods, and these macroalgaes will need light to survive.