Hello Paolo! Welcome to the FISD and congratulations on taking your first steps towards becoming a Stormtrooper!
When I was at your stage early last year, I looked everywhere, on YouTube and on this forum (mainly Expert Infantry and Centurion threads) to see which makers I thought looked the part! With your height, I don't see an issue with pretty much any maker, but a fellow Garrison member that is a little taller, he went with TM (Troopermaster on Facebook) as he can offer taller legs if that is something you're a little worried about!
What makers people choose tend to vary mostly based on the "width" of a person from what I've seen so far, and in the "width" department most if not all the vetted vendors offers good solutions on this, maybe except from the ROTJ armor makers as the armor itself isn't really made with shims in mind, but I'm sure that this isn't any issue for you!
As for the Hero and Stunt, it is of course based off of your own personal preference! When I ordered my kit from RS Prop Masters I couldn't decide on which one I wanted. I loved the Stunt but in my mind the Hero had etched into my memory as what the Stormtrooper should look like, since when I was a little tiny boy - I looked through (and pretended to read) the book "Star Wars: The Visual Dictionary" a whole lot!
Since the difference between the Hero and the Stunt is simply just the helmet and the belt, I decided to spend a little extra to get the Stunt too (I have yet to troop in it), it just felt awesome to be able to have the same helmet as most people wear, if I ever wanted to! If you are into accessories, the Stunt and Hero have different accessories available to them and that could also influence your decision!
Glory to the Empire!