QTR-Quadtone RIP

I'm looking to purchase the x-rite 810 densitometer to aid in creating
paper/ink profiles for QTR.  My question has to do with the
calibration strips that come with the unit.

If I find a good looking unit but it doesn't have the calibration
strips, especially the reflective strip, how do I calibrate the unit?
 Is there a simple standard that can be obtained elsewhere?  From what
I have seen the 810 calibrates for reflectance based on a "black", a
"white", and a "gray" patch.  Seems like these might be easy to come by.

Mike