So, what kind of cichlids? African or South American? I'm with Dave on the numbers. I've built two wet/dry's. I can say that I really recommend elevating a wet dry and letting it pour into a sump. That may seem obvious, but I have acrylic store varieties now, and I found out the hard way that having that sump makes all the difference in the world. If the power goes out, or your me and turn the pump off and walk away not realizing your tank is overflowing out of the wet/dry, it has a place to go. My wet/dry on the fw tank sits in a 35 gallon rubbermaid tub. Never had any problems with that tank, and I plan on adding a sump in the sw tank after my lessons in cleaning saltwater off the floor by the gallon.
I work in the food and beverage industry, and my solution to the trickle plate came in the solution of green pot scrubbers. They are for scrubbing teflon pans and plates without scratching them. They are about 1/8"x2"x4". What I did was stacked them up like a pyramid to help disperse the water over the drip plate. Works like a charm, and they've been in there over a year and are as good as the day I put them in, never cleaned them once either. So if you know anybody that works in a restaurant try to get them to hook you up. One lesson I did learn was that in sumps, water doesn't always get the proper flow. I added a powerhead to mine to get rid of the stagnant pockets.
If you end up taking the canister off, don't do it for at least a couple of weeks, for the bacteria. I figure you know this, but just wanted to mention it. I use my old school E-heim as a powered buffer; I stuffed it with peat moss and run my co2 into the intake. The whole thing sits in the sump, and the intake and out-take are both in in the sump, as it isn't really strong enough to push water into the top tank. What's your plan for an overflow and a pump?
Hope this helped, sounds like you've got a plan. Take pics during the build!