Any recommendations for a better option for a rear locker with what I'm reading I'm concerned about damaging in my rear end
First of all, are you sure you want a locker and not a limited slip? There's a big difference in handling if you drive on the street much, and especially if you ever find yourself on snow and ice.
I'm a huge fan of the Detroit Locker, and have them front and rear in two of my Jeeps. But those rarely gets driven on the road. I also installed a No-Spin (case-less Detroit Locker) in my Peterbilt, which is driven almost exclusively on pavement. With the weight and wheel base of the Pete it's a non-issue, but I can still feel it at times.
In other words, in my opinion a street driven M1009 is borderline short for a locker.
When it comes to limited slip differentials, the True-Trac is about as good as it gets, I think. It's unnoticeable, yet works. And it can be made to "lock up" with a brake application should one tire be in the air.
And after this long rambling, I have to admit that I no longer know whats available for a 10-bolt so I can't recommend anything in particular. But I would pay extra for an open diff over an axle with the bomb installed.
Can't remember what my conclusion was when researching how to defuse a Gov-Lock. As I recall, it wasn't as easy as removing a few parts in the governor. I think epoxying the thing shut was the most feasible solution. Installed a Dana 60 and called it a day.