Wet vs dry is personal preference, really. I like a wet palette because I do a lot of mixing, and it's a good way to keep your paints the right level of thin. I find dry palettes a pain because the paint consistency changes over time, which can obviously affect the way it applies to your model. Not to mention it's wasteful. In my experience, people who prefer dry palettes are just people who haven't bothered to give wet palettes a proper go; not that there's anything wrong with that, but there's not really any reason I can see to use a dry palette over a wet one for general miniature painting. Whatever floats your boat though.
You can use anything on a wet palette that you could use on a dry palette; a wet palette doesn't affect anything in the paint at all apart from water content. So if it's water soluble - you can use it. And if it's not water soluble, then you can't use it with acrylic paint in the first place
Oh and keep your homemade wet palette - don't waste your money on a fancy one, they are all identical in function.