@lukastribus, to tell the truth I was starting to doubt that my decision to spare some little money was worth risking to deal myself with DoS attacks, and of course charging my server with extra work did not seem after all a good idea.
Thank you for your suggestions.
OVH was my first choice when I realized that their client support is really poor: that was the reason why I was pushed to look for alternative solutions. I spent weeks to get replies via tickets, usually their time response was 5/6 days and they did not answer to my questions, having to deal only with sales representatives who did not understand technical questions and had no answers. So my attention was attracted by providers that offer chat support, and generally speaking better client support.
I apologize for this digression, but this is the first time I got the chance to speak about it.