Good questions and great feedback Jorge!
Yes, if you are going to add aerobars to your road bike, only do so if you are getting fit for them. And since everyone needs a professional 3D Fit, now is the time to get your aerobars fit at the same time. Please do not put them on yourself and ride with them without a proper fit. (Think high risk for injury if so).
As for a trainer, as Jorge mentioned, there are a lot of options out there and most of it depends on what you want to gain from the trainer and your price point. No matter what your price point, I recommend a fluid trainer because they are must quieter. Because there are so many options out there, what are other using? What do you like? What do you not like?