Where to get Wiper bushing/connectors

Did you read the first comment at that Summit page ?
I'll go ahead a clear the waters ( misconceptions ) for you and who ever else may be reading...
The original plastic bushings lasted somewhere between 20 and 40 years. When they do fail its always the same 2 of 4 that fail. There is a good bit of labor involved to replace any of them so most will go ahead and replace all of them. No fault there. Hundreds of owners have done so only to have bushing fail again within 2 years. The first thing they do is go online and blame the quality and/or materials used in those aftermarket parts. Truth is, the wear and subsequent binding in the left hand wiper pivot wore the original bushings and the aftermarket bushings. They fail because they are supposed to in certain conditions.
Chryslers from day one through 1967 had bronze bushings leaving virtually no point of relief. The wiper operation would become very noisy but more importantly, The wiper motor would draw much more amperage. This contributes to those typical electrical failures, wires and various harness connectors eventual melting.
Bottom line, Go ahead and replace the plastic bushings once. If they fail again in short term, the root of the problem is very likely in the left hand wiper pivot assembly. You'll need to replace that along with the bushings to get your happy moparing.