I recently purchased some new trainers and I have been very impressed with them. Check out the website here:http://www.takknife.com
They are made from polycarbonate rather than aluminum. In my opinion this has some advantages. First, the polycarb is just as tough or maybe even tougher than aluminum, and it doesn't get those annoying "burs" that can scratch up your training partner. It also seems that it allows for more designs. John has several knife designs that includes crossguards that you don't typically see on aluminum trainers. He also has a Vietnam Tomahawk trainer. An aluminum trainer looks like a steel knife, which can have some psychological training advantages for both partners. But it can also attract unwanted attention if you are training in public. The polycarb may be a more "politically correct" trainer in public places.
John has a large variety of models and told me he has more in development. He also does some nice custom designs. He answered my questions promptly by eMail and shipped promptly when I placed my order. He seemed like a really good guy to deal with and does good work. Check him out!