I have two sets of 1 2 3 blocks, I used to use them everyday for a previous job and I use them from time to time in the garage for setup work now. These are made within three tents of a thousandth (.0003") so they should be good for shop use.
Available here http://grizzly.com/ for $17 a set
Ranger 5.o, needing another project like Rosie O'Donnell needs another M&M.