According to your specifications:
1) We would like that user after purchase of one of those services could access to a private page where he can manage what he have purchased.
2) We would like to have freedom to put personalized content on user private pages.
3) We need in particular that a user could use a contact form tu send us extra information on services configuration.
Solution:
1) woocommerce + some page privacy settings
2) wordpress configuration
3) a contact form ?
I would say you don’t need BuddyPress for that. Confirmed by your statement:
We don’t need to have interaction between user, like a forum or a social network.
Read about BuddyPress.
