Bricks, Masonry, Asphalt and Concrete - Blue stone over concrete

have blue stone or slate in my den over concrete slab. Had to dig up part of it to fix radiant heat copper tubing in the floor. Now I want to reset the stone. The hole is about 8" x 4" x 4" deep. I've never worked with concrete before. Can anybody recommend what I should use? Sakrete seems to have about 10 different products. I also need to reset some stones, Tennesse face stone it's called, in a curb out front that's crumbling from cars hitting it. Would I be able to use the same product? Whatever I get for the floor is going to be way more than I'll need for a 8x4x4 hole I'm guessing so if I could get one bag for both jobs that would be great. Also in that same den floor I have a few loose pieces of slate and some loose mortar on the steps of the same stone. Is there some kind of bonding agent I can use to firm them up/reattach the mortar chunks?
Any help would be greatly appreciated.

Mark

This should take care of both your needs.

http://www.quikrete.com/diy/PittedChippedConcreteSurfaces.html

The second half of this appears to address re-setting the stones you have with mortar on them.

http://www.quikrete.com/diy/RepairingSunkenBrickorStoneWalks.html

Hope this helps.