Photoguy, you're on the right track. The L4400HST will tread more lightly than any of the Grand L's while giving you enough power and lift capability for that 5' Med. duty brush cutter. The smaller Grand L's are built on the same basic chassis as the
L4400 anyway, the wheelbase is the same. But they do weigh more and cost more while generating less power. The paper improvement in 3PH lift capability is only a few hundred pounds and that's academic since the
L4400 has the muscle...as long as something holds the front down.
The only issue is with a 6' med duty mower. It'll still work, but the rig will be unbalanced, you'll feel it and it'll make you uncomfortable. I'd be surprised if the smaller grand L's are rated any higher than the
L4400 in terms of mower capability. Maybe someone here can look at their
L3240/3540/3940 manual and tell us. I know the MX5000 is rated for a mower maximum of 84"/1000# and that's with a 3PH lift capability that's exactly the same as the
L4400's. It's just a little longer and wider than the
L4400, as well as being about 500# heavier, so it can handle the added weight better.
BTW are you going to leave the tractor and mower out at your prairie site or will you trailer it? With tractor, loader and mower you'll probably need a 20 footer to trailer.
Bob