I bought the Accel 150821 injectors from
Summit Racing.
The price on the Summit site is @ $295/8 + shipping, and you'll need a plenum gasket from Jerry's gaskets, and he provides an O-ring set too.
Note: The Accel 150821s have a plastic key tab that has to be filed off in order for the secondary connector to snap on. No biggie, but you might want to know that, should you go that route!
I don't know if the $750 for FIC includes the gaskets as part of a "kit", but if it does, the costs are about the same. However, Jon at FIC is a supporter of the Registry, and for the same or nearly the same $$ between Summit or FIC, then personally I'd give Jon the knod for being a supporter.
As for test procedure to observe the secondaries, there is a procedure on Marc Haibeck's site;
Haibeck Automotive Inc.(?). Lots of other great info too!
P.