It all depends if you want proper Jousting ( go for Destrier ) or just fancy dressage
And what level of entertainment you want.
The contact jousting a-la Destrier is of course more authentic etc, but the fancy dress jousters can usually be more entertaining. (more speed, and less waiting)
Just my thought after watching both types, and both types have their place.
Young men have often been ruined through owning horses, or through backing them, but never through riding them: unless of course they break their necks, which, taken at a gallop, is a very good death to die