Thanks for your elaborated answer!
You are right, what I am thinking to do is two separate things. Studio and Tour.
Tour is not a big issue to be honest, is just metronome and some audio effects with some samples, quite easy.
Studio music production is what I am not sure, on the topic of Reaper, I am planning to get some of the music libraries of Komplete Kontrol, make some sample usage, write music with lets say some synths, then drums, then bass, just usual stuff, but if someday I use lots of libraries that is where I could get concerned. I will be glad to work in writing the music without any concerns (or the less concerns).
So basically GPU is out of the equation, that is something I really wanted to know of guys like you that have more experience than me on this, because I have been a musician for more than 18 years but I NEVER sat down and tried to struggle with computers about getting this thing done.
So main role for the Laptop in studio is Everything, I may record acoustic drums and some guitars, but everything else will be composed with sample libraries.
On tour, it is with another whole different band that doesn't needs this so, that is out of my concern to be honest.