ZBrush is good for manipulating existing models but I would not want to make clothing from scratch in it. Of the others each will do what you want. I use Truespace ( http://www.caligari.com )which you may want to consider. In my opinion it is essential to try a demo before you purchase. I tried several before going with Truespace. All did the job and had similar features but for me Truespace "clicked" so I went with that.

As for UV mapping, I've found the best bang for the buck is UVMapper Pro ( http://www.uvmapper.com ). There is a free lite version on that site you may want to try first.

Hope this helps.