It depends on the amount of work you have to do and your ability to run the equipment. I've seen tractors with the backhoe attached to the three point with out any problems for years.
I've also seen frame mount configurations that with the right operator have hurt the tractor as well as the hoe.
My preference for the 7800 is the BH75 as it sit's closer to the tractor so it has less leverage to be able to cause any chassis damage. The power is good and they are easy to hook up.