What size mower

I tried an Uncle's 6' brush hog once, but it was just too big. When it was raised up, the hydraulics knocked loudly. And you could walk around to the front of the tractor and pick it up easily. (No joke)

So I'd stick with a 5' mower to be on the safe side. All the 4' mowers I've seen have been pretty lightweight.

Would it be either a single or twin rotor blade (blade spins horizontally off a vertical shaft)for topping pasture etc.

or same type with smaller lighter approx 21" blades (finish mower type as used on compact tractors).

or flail type (horizontal drive shaft and rotor with L shaped flails attached)

or either a disc, drum or fingerbar mower as used for hay making.

The problem is that i have also been offered a 6 foot single rotor pasture topper and it looks massive for a fergie (horizontal blade vertical shaft type)
While i have used a 6 ft fingerbar mower successfully but it obviously doesn`t mulch the cut grass, and i doubt a fergie could drive a 6 ft disc mower. thankyou