You may find with a little shopping you can buy the factory pieces plug them in and get factory cruise for less than $100
The cruise in these cars looks identical to what my Yaris now has. The yaris didn't come with cruise. I had to buy the plastic cover for the steering wheel, the stalk, and the clutch switch to disengage and that was it. Came to less than $100. Everything was plug and play.
Now the big thing will be if the ECU on the car in your country is already programmed for cruise control. The yaris in Canada was, but in EU it wasn't.
This is a link to what was done for a Yaris, and absolutely no guarantees it would work for you in an FRS....
http://www.yarisworld.com/forums/showthread.php?t=33750