Hi Coot,
Few years ago I was contemplating the same situation.
Most manufactures of brushing heads will claim that small machines (under 10 ton) will operate even their smaller
attachments, scale down the attachmentand you get dissapointing production. Bottom line is that smaller machines dont have the flow required
to run flow hungry attachments. Kubota 080 claims 18 gph, probably the highest in the field but everything suffers, flow diverter dosent work well either, you are constantly dancing on the switch so you can articulate then cut, repeat...
The solution I resorted to was to build an aux power pack based on a deutz 55 hp diesel, matched variable displacement pump to the cutter motor. Run it at 1800 rpm (max 2800 32 gpm) all day producing 22gpm at 4500psi, no extra wear and tear on the carrier hyd system.
4 bolts hold it on and an umbillical providing fuel, 12v from the carrier. Cab mounted pannel/murphy switch
One issue: smaller machines get a little squirrely on steeps with 1000+ lb attachments,
Im running a 1000lb AFE on a komatsu 75, similar Fecon is heavier (1200lb?)
It will cut circles around a 315 all day though!