tobster, I think you are putting yourself under too much pressure by setting your 17th birthday as an "ultimatum". My advice, begin JAR-PPL training, include in it the tail wheel training as had been already suggested, and take all the time you need for it, without pressure!
Tug (or tow) aircraft are often larger (=more weight) then NPPL allows (in Germany, max 750 kg), so you would have to get the 2000 kg rating on top of it anyway. And by next year, with the EASA licence, it all may in the end cost you more!
Good luck, whatever you decide!