Scott,
It's funny that you posted this. I just ordered my second set of scissor jacks for my Roamer. 5000lb rated and they open to 24 inches.
I put a set on my Mesa with self tapping bolts and they worked just fine. My friend does some welding and he offered to spot weld the corners of the jacks, so I took him up on that. But I do believe that self tapping bolts would hold those jacks on with no problem. After all they're only meant to be stabilizer jacks.
I really hated the old jacks so I took all four off and put on the scissor jacks that I raise and lower with a cordless drill when I go camping. So much easier. I say go for it I have loved having them on my Mesa. Like I said I just ordered a set of four for my Roamer. Bal Low pro. SJ24 Scissor jacks. I should be getting them any time in the mail.