Learn on the trike gear trainer. It will help protect your prop/engine when you make rough landings when you are learning (trust me, you will have them). Switching from a trike gear to a taildragger in your second plane isn't near as difficult as some people think. I see too many people think like you that they need to learn on a taildragger because that's what they want to fly. But taking off and landing a taildragger isn't any harder than a trike gear, just a little different. But the differences aren't big enough to lose any sleep over.

At least that's my 2¢ worth

Ken