Yup, all the Dulux Weather Sheild stuff is tough. It's exterior paint, so it'll take a beating without fading or chipping, and is especially recommended for tabletops if you've got mates drinking around them, or resting beers on them.

Mohair will give you an ever so slight texture to your cab. If you want perfect mirror finish, then you've got no choice but to invest in a spray unit. You can get airless spray units which make cleanup a heck of a lot easier, and give you less splatter. Pressurised air units are far easier for large surfaces, however.
Also, if a mirror finish is your goal, then you need to do a hell of a lot of sanding in between coats. Either that, or get your initial surface nice and smooth to start with, and head for two pac. Of course, that stuff is pretty damned expensive, but gives a superb finish.
It's pretty easy to go overboard on your paint job. Cost wise you can spend anything from $20 to $200 easily for a variety of finish qualities. It all depends on how much you care about the finish, and what your budget is.