best-time-to-visit-costa-rica-and-nomad-america-4×4-rental

First of all, in your opinion what is the best time or month to visit Costa Rica (including the balance between the amount of tourists the dry season and the dry season for real)? Second, I was searching about ways of traveling in Costa Rica and I found a company called nomad America that rent a 4×4 with all camping needs (to cook, tends to sleep and other things), do you know this company? Do you thing its a good way to explore Costa Rica? Thank you, Inês