E&G is good and local.
I picked up the kit of Weather-tite connectors from Summit a while ago. I don't use a whole lot of them, but I periodically restock it.
Besides Parts Express there is Waytek and Delcity. I've also used Wiring Products, which is smaller.
"Why does the U.S. care which flag will be hoisted on a small piece of land thousands of miles away?" -- Ron Paul