what type of wet dry? They can work ok but they can also become nitrate factories, so if you use it, you will need to stay on top of cleaning the bio-balls or other media regularly. A refugium is a place for you to grow macroalgae and produce pods or other live food for the tank. The macro will help remove nutrients from the water as it grows and if you place your fuge light on an opposite schedule from the DT, it can help stabilize your tanks PH by keeping the photosynthesis process going throughout your tanks "lights-out" period. It also increases the overall water volume of your tank which can help stabilize parameters. Additionally, some people have a deep sand bed in their fuge. You'll want to do some reading on the benefits and pitfalls with a DSB if it something you are interested in. The only negative thing about having a fuge, is the space it will take and the cost of setting it up. Well worth it though if you have the space for it! How many watts, or what type of t5 fixture are you planning to get? The t5's should be fine for softies. I'd suggest you spend a bit reading up on the sterilizer as they are not typically run 24/7. It can be a great tool, but you just need to make sure you understand how to use it properly. Not sure what type of reactor you have, but you wont need it right away, and may not need it at all if you are just keeping softies. Otherwise, the two biggest things that you haven't addressed are flow, and live rock(LR). LR will be the most important filtration you have. You need 1-2lbs per gallon. I assume that you already have some since you said you are cycling? For flow, you will want somewhere around 10-15x your tank volume for softies, more if you start keeping LPS and more even yet for SPS. Just make sure that you have sufficient water movement.
