Since I'm in the process of building a custom wire harness for my build and have been searching for sources for OEM connectors w/ the necessary pins I thought I'd share the sites I've found so far. If you know of any others feel free to post them up here
EasternBeaver - A lot of our connectors are the Sumitomo DL series
http://www.easternbeaver.com/Main/El...SMDL/smdl.html
OnlineComponents.com - ECU connectors and pins
(1) 64 pin ECU Male Receptacle PN: 174518-7 (oem harness plugs into it)
(1) 22 pin Female Plug (plug into ecu) PN: 174515-6
(1) 26 pin Female Plug (plug into ecu) PN: 174516-6
(1) 16 pin Female Plug (plug into ecu) PN: 174514-6
(16) .070" contact PN: 173631-6
(48) .040" contact PN: 173716-1
changing the -X changes the material used or color, so if they don't have in stock search for it without the -1 or -6.
Ballenger Motorsports - great kits for individual connectors/pins but just like any of the other sites, they're not all there
http://www.bmotorsports.com/shop/mazda_miata.php