Stock 14" Tire Replacement - 72 Dart

Hey Guys -
Picked up my 72 Dart Custom 4-door last night, and the ride from Birmingham to Atlanta was a handful on these old Goodyear Polyglas Belted D78-14 tires.
Not only was I worried they would come to pieces, but the car acted like it was feeling every little groove in the road, and wanting to dart all over the place.
Not sure if the darting around could just be these old tires, or if the shocks and/or alignment could play a part in that.
I haven't checked yet, but the car only has 55k original miles, and the steering seems good and tight, with little to no play, so I don't think it's going to be work steering parts.
Anywho, it looks like the recommended tire size to replace the D78-14 is a 195/75-14.
As most of you know, 14" tires grow increasingly expensive, so I'm wondering if there's another size that is very very close, but may be noticeably less expensive. I've seen countless times where you can go to a larger tire, and it's actually cheaper, because the smaller one is used by so few people (supply & demand).
Also, I'm wondering what's the largest size I can put on these stock wheels, and have them all 4 be the same size (so I can rotate them properly), and not have them rub.

Thanks for any info.