We actually have two changing "stations" -- one upstairs and one downstairs. I use a regular diaper pail (because the step-pedal garbage cans all seem to break easily, but this pail by Safety 1st
has lasted us nearly three years, no probs, and it's cheap). We have four pails now: two for CDs and two for garbage, because they work better than garbage cans.
No matter which type of pails you go with, or if you choose a regular plastic garbage can, make sure it is NOT airtight.
We use nylon laundry bags as liners. I wash them with the CDs but hang to dry. They are not waterproof -- they are breathable and have holes. You ideally don't want to store wet or dirty diapers for any length of time in a waterproof, airtight container. That breeds mildew, which will ruin CDs.
Wetbags for me, are fine for occasional use, or if you don't close them up all the way, as long as you launder regularly. But most people I know hang their wetbags, which means they're closed up and no air gets in. I wouldn't use one regularly because I only wash CDs every 3-4 days. So for me, using something that is stored in a breathable container works better. But for someone who washes daily or every other day, a wetbag can work just fine.
I use a gallon Ziploc for my wetbag in my diaper bag. I've used the same one for over a year now. I just rinse it out and reuse it.
But I'm cheap.