'07 M8 rear suspension update

Couple questions......I want to update/upgrade the rear suspension on my M8.

1. Can I upgrade the suspension components or should I also do the whole skid?
Any benefits to either?

2. Should I go OEM updating or aftermarket? How much price difference and is it worth the extra cash, assuming aftermarket is going to be more $?

3. If I go the route of OEM, are all mounting bolts in the same locations or will there be some modifications. And, up to what year will they match up if they do?

thanks for any info.

Cool, thanks. That's some of what I was looking for to start. Now, I'm guessing that pricing will come in to play and the differences between the float conversion and after market in terms of how they perform. I can feel a big difference between my 07 and the float on an 08 so there could be that same difference with the others.