Gerald pretty much covered the PE/resin/home-made options. I'm about 95% done on a KT using a Cav set. I also have a Tiger (P) with a PE set....The PE set is pretty "stiff" and shows no "wear and tear," so if you want a "factory fresh" application, PE will work. However, if you want a kit that's showing some beating, go with the resin. It's flexible, easy to trim (very much UNLIKE PE), and easy to use. While doing the KT's zimmy, I used a combination (depending on piece of zimmy to attach) of 2-part epoxy (great for the larger pieces), Future for small flat pieces, and Gel CA glue for the small pieces that go on rounded and complex surfaces (mantlet and the like). From what I gather (and I could be wrong) the big difference between Cavalier and Atak is that Atak will often include a zimmy'd turret, so most of the complex surfaces are already done for you.
HTH,
Mike