My little Kukje tractor has similar dimensions, although it weighs nearly 4,000 lbs as just the tractor.
The loader and bucket add 1,300, loaded tires maybe another 1,100, the little hoe on the back adds another ~1,000 or so == could be 7,500 all up with tool box, fuel, etc.
The trailer is rated at 10K, has 16ft bed, with 2ft beaver tail.
It barely fits with the Harley Rake on, I have to jigger the ramps around.
I don't know what the trailer itself weighs, hopefully under 2,500 (-:
Fortunately my truck is a flat bed, so if I take it anywhere and need 2 or 3 implements I have about 8 ft by 7ft clear deck space on that.
I wouldn't go any smaller than 18ft total deck length for a Cat 1 tractor with an implement.
I don't have a rotary cutter, my Caroni flail is plenty long enough on the trailer, a 6ft bush hog would hang WAY off the end - or the bucket would have to go over the edge at the other end.
Yep, a 20+ ft Goosie would be nice.
I have a head to head horse trailer that is 30 ft on the floor, with another 8 1/2 ft over the truck.
A similar dimension equipment trailer would be nice to have, not TOO cumbersome - but then I would probably just put more on it,
maybe a bigger tractor - everything fills up (-: