Hks, Blitz or GReddy all do very good ones that have loads of functions. If you also buy the harness specific to your car (its about €25) you can just plug it straight in. You will probably have to wire 3 wires so the extra functions work. 1 wire to the wire going to the hand brake lever, 1 wire to the rev wire and 1 wire to the speed wire. When wiring the hand brake wire wire, if you wire it to the handbrake cable, the turbo timer will ONLY work when the hand brake is up, alternatively you could just wire it to a negative wire or ground it to the body of the car it will work whether the hand brake is up or down. Hope this helps