Hi rstermer
Well they make some good ones but they are not cheap but I always say if you want the best make your own.
I order some last week, see below,, but he has all types at the right price..
http://cgi.ebay.com/ws/eBayISAPI.dll...m=330233029881
Just a note****
You can buy the tee nuts that just slip in just right but they are about .40 cents each and a Sq. nut will do the the same job at .03 cents ea. plus a carr. bolt for the stud type fastners at .04 cents ea.
It's the same stuff they use for many jigs..
like the one below, the ones below are 2" tall that has been stacked up to 4" tall with 2 ea.,parts with a 1/4" pin down the center to keep it true...
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