Are you positive the tire size is a 205/50/14? To my knowledge no 05 Focus ever came with 14 inch wheels nor do I believe they could fit them due to the brakes being larger up front.
The stock size on the car would be one of two sizes. Either a 195/60/15 or 205/50/16. The first size was mounted on all cars with steel wheels and some with 15" alloys. The second size was for all the 16" alloy equipped cars.
I believe the ZX4 SE's all came with the 195/60/15.
The crucial thing here is we really need to know exactly what the wheel size you have is. Then we can recommend the correct size. Websites don't even list any tires in the 205/50/14 size. It would be a very strange size.