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.
'91 Toyota Pickup
'09 Kawasaki KLR650
'12 Gunnar Rockhound 29
"To live is to suffer, to survive is to find some meaning in the suffering." -- Friedrich Nietzsche