Its quite easy to install a turbo timer. I just installed mine and i was suprised how easy it was. if your keen on fitting it yourself check this out. i followed this and it works fine
http://mkiiisupra.net/bbs/showthread...ight=guide+hks
And you can use any turbo timer not just the one he used. i used a GReddy Full Auto Turbo Timer and just hooked up the handbrake wire as i didnt no which wire in the ECU to splice into. And it works great
Hope this helps ya mate