How far apart are the two terminals? Are we talking inches or feet? I agree making them yourself is probably the simplest way to go. If you use a "stackable" plug for the first one, you can just plug the second wire run into the first one. They aren't cheap though it seems. I use the Bluejeans locking ones as well and I am very happy with them, though they are not stackable.
The easiest way I believe would be to get a banana that simply accepts a large size wire so you can just connect the second wire into one plug. You might give the 091-330 a look at
www.partsexpress.com I've used those and I like them too, and the side entry should accept plenty of wire.