I've had a 70s model 63 for a good while and in the past have owned a couple of 34s, the original blue steel version. Like all J-frame guns, these have never been the easiest revolvers to shoot well. Many quickly dismiss them as being inaccurate, but really, a shooter's deficiencies are the problem.
Use good technique and practice with these guns at 25 yards. You'll be quite pleased at how well they shoot.
Like all .22 handguns, a number of ammos need to be tried from a benchrest, again at 25 yards. Shooting closer will tell you nothing useful from an accuracy perspective because everything shoots well up close. You will find a measurable difference in group sizes. Go with the most accurate and don't worry about whether it's high velocity, hollow point, plated or any else of little consequence. After all, it's a .22 rimfire.