Bob,
Unless you really want the proportional brake, the jet-tronics valve is definately not necessary and I would say a wasted effort if you have the wheels/brakes from Tam. Those brakes work wonderfully with just an on/off function. Otherwise Dave's tip is probably the best route for both the brakes and gear.
What I found to work as well was a piece of plastic tubing like the clear type you route a reciever antenna through. I had the same problem when I first tried to hook up that valve. I just put about a one inch piece in the festo fitting and just connected the airline to that. It was a makeshift effort but it doesn't leak and I have never changed it to something else because it works just fine.
Mark