The Tamiya web site doesn't show any enamels. They show acrylic and laquer sprays, but no enamels. Here is the link:
http://www.tamiyausa.com/product/paints/index.html
I really like Tamiya acrylics, but as you say, they just plain dry too fast. I normally airbrush just about everything, but I have been able to improve hand brushing with acrylics (specifically Tamiya) by thinning the paint a LOT. In fact I thin it almost as much as I do for airbrushing it.
Tamiya thinner states on the bottle that the ingredients are an "Alcohol Mixture" but I think they may have some retarder in it or something because it really helps. I've tried plain isopropyl alky (which is what I normally use for thinning it for my airbrush) but the Tamiya brand works much better for hand brushing.
I usually put a few drops of paint in an old film canister lid. For every four drops of paint I add 1 drop of Tamiya thinner (I told you I don't hand brush much!) and that seems to work pretty well for me.