Ford 4000; Ford 2000(both 3cyl.);JD40; 2004 Kubota L4300; 2006 Kubota B7610; new 2007 Kubota MX5000
6 foot works really well, but be careful with the weight. A medium duty 3 point 6 footer will run close to 1200 lbs and if you try to lift it you'll need alot of suitcase weights or the FEL to keep the front wheels on the ground. I believe the weight limit for a bush hog on an L4400 is around 880 lbs, same as my L4300.
Standard duty 6 footers are around 750 lbs. Should be no problem.
Bob
I would agree. Stick with the 6 foot standard or medium duty that stays within the 3pt hitch rating. I have a JD LX6 (considered a light duty mower but weighs as much as some mediums) and it works well and balances well with the FEL on.
With a pull type mower you are mainly limited by how much PTO horsepower you have since they don't put any weight on the 3pt. I've run a heavy duty single spindle 7 foot pull type behind my L4400 through thick waist high brush with no problem.