Both Dow and Owens Corning make foam board in sheets with recesses pre-formed into the foam board for 1x3 strapping, so the 1x is flush with the foam surface.
The OC product is called Insul-Pink. and is 1-1/2" (R-7.5)... it is marketed for basement finishing, but can be used above grade over studs.
Dow makes a similar product in 1-1/2" and 2" with R-Values of 7.5 and 10.
I rip my own 1x3's out of 3/4" plywood. Here is a pic: