If I had the money, I'd go with Furuno, all through. That's what most commercial fishing and workboats use. If you check out used radars, Furuno seems to be the longest lasting gear, finally getting replaced. I assume a complete suite of Furuno electronics would be at least a couple of grand more than Garmin.
I've no experience with the modern B&G gear (parent company; Navico), but their old stuff was excellent and market leaders.
I would not install anything by Raymarine, if you gave it to me, AND paid me to install it.