RE: Nitro trainers...
Of the ones on my list I usually shy away from saying what is "best". They are all good trainers, that's why they are on the list in the first place. But if I was forced to pick I would tell you what I thought the best value is, it would be IMHO the Tower Trainer. You can pick up the ARF for $69 and it's an outstanding trainer. I have taught many students to fly on the Tower 40 (it's what I learned on as well) and they all do well with it. I've been flying for 12 years now and I even still have my Tower Trainer, I take it out every now and then and fly it.
Overall, like I said, everything on the list is a good trainer and you will do well with it. Just make sure you find yourself a good instructor because without one no matter what trainer you have you'll more than likely be bringing home in a bag.
Ken