Is your JRT a male or female? Age? How is he/she around other dogs? Terriers are typically "tougher" by nature of their breeding. You really don't want 2 alpha personalities. Do you care about size? Do you really want one from puppyhood? There are a lot of great dogs in rescue.
You might narrow your choices down to a few breeds and then see if you can meet some examples, maybe a breeder or club gathering.

Flat Coat Retreivers are bidable and easy going. I would shy away from another terrier breed if you are already having trouble with their training style.

I have known a couple of Wired Pointing Griffons that were eager to please. I believe there's a few more of them in PA than in our region.

Most sportingspaniels are going to be very willing to please. There are a few indepents buggars out there. Very loyal and bidable as a group.

Herding breeds, Border Collies, Aussies, Shelties need a job, no have to have a job. They're very smart and can really take a lot of work because they are too smart for their own good. Have known and loved a few Aussies in my time.

Not a huge fan of toy breeds because they don't fitour lifestyle and my dogs would probably try to carry them around like ragdolls. Italian Greyhounds are sweet but frailand Cavalier King Charles Spaniels are very devoted family pets.