I'm looking for a website where I can get technical advices from people in the profession.
Not 100% professional members, but you could try: http://www.thecomicforums.com
You could also sign in for the Area 51 proposed pages, for example:
Making Comics Proposed Q&A site for artists, writers, comics makers, on all supports, with all narrative styles! http://area51.stackexchange.com/proposals/9271/making-comics
Art Creation Proposed Q&A site for artists, painters, drawers, caricaturists, illustrators, cartoonists, graphic artists, engravers, sculptors, etc. Basically art techniques and methodologies. http://area51.stackexchange.com/proposals/7250/art-creation
I'd also say http://www.deviantart.com/ , because it has great artists and perhaps you can contact some of them. I'm sure lot's of people would give you their opinion. And don't rule out comic geeks, they can give you an expert's idea too. Good luck!