OK. First off, you have a reef. How much LR do you have in the reef? As long as you have 1.5-2# of LR per gallon, and lots of water circulation, you shouldn't need anything but a protein skimmer, theoretically.
Wet/Dry vs Canister?
NEITHER
Both are nitrate producing monsters. I would go with a refugium/sump with a good protein skimmer in it. Go out on the web and look at all the showtanks and displays in books, mags, etc., maybe one out of every 30 or 40 will have something other than a refugium.
I had an Eheim on my tank when I first started my tank and only had like .5# LR per gallon. It wokred great, but my nitrates took a nose-dive through the floor when I took it off.
If you are going to use one of the two items you are asking about, make sure you change the filter pad every couple of days, week at the most, on the wet/dry. I would also suggest cleaning the Eheim weekly if you get one. BTW, the Eheim is cool, but it surges. The water level of your tank will go up and down with the cycle of the filter. It is cool for a little bit cause it is a wave maker, but surface skimming is impossible. Good luck, whatever you decide. There should be plenty of threads about fuges on this and other sites.