I've got the 7' (84") HLA plow and Aquiline MPC chains on rear only on my DK-40. Had it for three years, possibly 4- IIRC, this season, and it is excellent. No complaints. I usually have my backhoe on the rear, and that adds 1000#s of ballast, but last winter I had just my BB and was going to add ballast to it, but we had NO snow to speak of so I didn't do any real plowing.
I would go with the smaller plow for your rig, IMHO, the CK is less likely to get beat up by the heft of the lighter 72" plow. You won't be hurting either model plow- they are very heavy duty, and the crossover valve keeps the loader from being wracked by twisting forces; (which for your tractor's loader is no where near as strong, ( read resistant) to twisting forces encountered when plowing heavy wet snow as is the DK's loader.
Think about moving things with the FEL. The forces are mostly in lifting, and the DK-40 has significant capacity even over it's close cousin the DK-35, in lift capacity. More lift capacity via beefier loader arms, pistons, etc. The CK can't compare; that's not a bad thing- it's just a different machine. Consequently, the damage you could do by lateral twisting forces by slinging to big a plow could render your loader into dust; again just my opinion, but I can say I wracked my DK-35 loader, before I traded up to the DK-40 at about 350 hours and less than a year's use, through inexperience and pushing it too hard, and not even with a plow blade, just misuse of the loader.
YMMV.
Part of what I would suggest is tell us what your intended use is: home/farm use, or commercial? This will help us help you decide. You can't go wrong with the HLA plows- they're GREAT at doing the job!
