Your wish for 4 of the same size tires is popular topic on the tire forum. I know because I also am on that mission , and read most of the posts. I have concluded that a 5.5 or 6 inch x 15 is probably the most practical wheel to use. I believe you will find that 185/60/15 and 195/50/15 are the size tires that have proven acceptable.
The tires of these 2 sizes have been somewhat limited on the net and those getting high reviews are on back order. My wants were for a tire with good traction wet & dry and quiet. Your question about a 195/55/15 is what I wish someone might be using. The diameter is probably less than an inch more and could mean rubbing, speedometer change for certain or other issues, does anyone know?
The plus side of the 195/55/15 would be about triple the number of tires to chose from, but will they work?