I use a 54" front-mount de-thatcher that has graduated upward with my tractors since I owned a JD 445. I de-thatch and mow my thatch with the mulching deck on my tractors. Never had a problem with rocks as the guide wheels can be set to keep the tines at various depths. Turf specialists advise to de-thatch with your tines at least 1/4-1/2" above the soil. That way you do not harm the crowns of the grass plants. The tines can be dropped (wheels raised) to become agressive for seed bed prep or incorporating grass seed after overseeding. The original unit used a manual lift with helper springs and could be locked in a transport position. I've had a low priority project to have a welder create a bracket that will interface with my front hydraulics for my snow blade.
If you can find a front-mount from JRCO or and old JD model that you can adapt to the front frame or other front brackets, that would be your best bet. It's not a durability issue like using other light-weight L&G attachments on a CUT. 54" is plent wide for occasional dethatching of 4-10 acres of turf. You really aren't supposed to be de-thatching more than 2-4 times each year. And both the JD and JRCO unit are plenty heavy to be pushed around your yard a few times. Perhaps JRCO might build a proto-type for your for a reasonable cost. There are a lot of BXs and other CUTS out there that might present a good market.
Remember, your lawn need some thatch to stay healthy, keep weeds from germinating, and hold moisture in the soil during drought.