Tire size question

I have bad alignment which has worn my left front tire, so I'd like to buy a pair of new tires to put in the rear and move the rear tires to the front.
However... my question is this. The tires on my car right now are P205/55R16.
The suggested tire size for my 2005 Ford Focus is 195/60R15

Should I stick with the same size I have now or is it ok to put the new 195/60R15 in the rear and the (still good condition) P205/55R16s in the front?

I was thinking that next time I buy another pair, I'll rotate them and then have all P195/60R15s on the car.

Anyway... any thoughts?

Well you can't put 15" tires on 16" wheels for one. If you already have the 16" wheels there is no point in buying another set.

As for the size itself the recommended tire size for 16s on your Focus is 205/50/16.

The 205/55/16 is 24.8" tall. 205/50/16 would be about 24.1" tall. The size on there now is about 3/4" too tall. If you're going to change size now I would change all 4.