My C5 can take 17D731M or 17D731MHP front pads (semi-metallic)
or 17D732M or 17D732MHP rear pads.

Whats the difference between the M pads and the MHP pads?

The MHP pads are less expensive.

do both kits include the metal hardware needed to install the pads to the calipers?

How do you compare them to the OEM pads which are more expensive?

Wow, i've never seen so much thought put into brake pads in one post...get ceramic pads, you won't regret it. Yes every brake pad kit comes with new hardware/bracket.

One last thing, don't spend LESS money on something that's not oem. Think about quality over price.

Tried ceramics on my Suburban. They were noisier, no cleaner (wheels) and didn't last nearly as long as Raybestos Brute Stop pads (50,000+ miles for $50). In over 400,000 miles on the vehicle I've tried about everything.

And that $50 can be a one-time expense with a Pep Boys or Checker/Schuck's/Kragen lifetime warranty!