The Janome that I got was the Horizan, and the dual feed is built in.
Going to try to get it set up today,so I can at least look at it, but have to put one up first I think.

I have had my Pfaff for years with the dual feed and I am very pleased with it.

What about the Juki TL-98Q anyone? I've been researching machines and came across this one. It's in the $800 range and is a straight stitcher only. Doesn't have a long jarp, but a a very high one to accomodate a rolled quilt. It appears to be for quilting especially, for FMQ and piecing.

Baby Lock also have a dual feed system.

Elna has a machine with a built in dual feed, I don't have that newer model but I love my Elna. I would go see dealers and see what they have that you want and test drive every one that you want.

My Janome 6600 is wonderful. I have three feet that can operate with the dual feed (walking foot). The walking foot is attached to the sewing machine. You lift the presser foot and swing the dual feed-walking foot into the bottom of the presser foot. Very easy. I love the built in walking foot. Works great!

Elna is now made by Janome. So the Elna 740 eXcellence is the Elna version of the Horizon by Janome, and the 7300 Quilting Queen is the Elna version of the Janome 6600. Few different stitches, but same basic machines, both with Accufeed. The 7300/6600 don't have free arms. The possible + for you with Janome/Elna might be the drop-in bobbin, if a vertical bobbin is tricky because of your arthritis. Bernina's walking foot us very easy to install and remove, btw. No screws.

I have always owned Pfaffs, and the reason is their dual feed. When Pfaff went bankrupt and Viking bought them, that ended their patent. Several other brands now have this feature. I'd take cotton samples with 6-8 crossing seams (star center) and denim with a crotch seam (yeah, I know you may never sew pants) and give each machine a try. And take two long strips of cotton and see if the ends match up after sewing without pinning. The dual feed foot should not be visible to the stitcher and be easy to "pop" into place in the back of the foot.

Sandy Quilts

Bernina now has one

I have the Pfaff2056 with IDT and I love it!