[OnlyMateo]

Yeah I really agree about MS Office + PDFs. I just want to find some online service: 1) where I can put the proposal (and where can the client download it from) 2) where the client can view the proposal without downloading (as I think it saves a lot of time) 3) and, may be, where the client can make some comments or leave some questions

I don't care about someone steals the proposal I just want to give my clients and my team the best way to communicate.

[HomeDeLaPot]

Sounds like there's no need for clients to log in. Maybe all you need is something like Google Drive or DropBox that allows you to create an unguessable sharing link for a folder. (Not sure if either of those do, though. Also not sure how commenting/feedback would work.)

[OnlyMateo]

Yeah thanks. I think about it and keep searching)