if you want a go, nogo, field, ptg sells them individually or as sets.
If you want a match set, ie, one for each .001 of headspace, your stuck with manson and forster. I personally don't see the point of a NM set, anyone chambering barrels should be able to measure a standard go gauge and figure out what your HS measurement it. If your just checking/ measuring HS without pulling the barrel, its not like you can change it anyway.
These guys offer gunsmithing gauges and other stuff. I assume this is ptg. Someone once told me of a company that would rent out gauges but I can't recall the company, apologies for extraneous useless information. http://pacifictoolandgauge.com/