I've used the Firestone wideoval on my old Galant and they were great for the price. Good everyday driving grip and wears pretty good (I quite often used them to go hills driving and they held up ok). And seeing as its going on a magna im going to assume your not after grip performance here. They were $180 a tyre for an odd sized tyre, so these should be fairly cheap.
I've used some yokohamas of the upper range which were excellent, but i know nothing about the lower A.drive models.
Turanza and the Khumo KU series are good, but for the model you are getting they'd both be around the same grip levels.
To be honest, for the car its going on and the type of drving (im assuming daily city driving) you probably won't notice much of a difference, but if I had to pick, I'd choose the Khumos first, then the Turanza at a very close second.
Also the most expensive consumable in a car is probably petrol