well for the heads, i am copying Jack Laverty's setup but with a turbo profile (cams) rather than n/a. the turbo setup costs more since you have to install valves that can stand the heat of the turbo, so i used nimonic alloy for that
as for the timing belt, since this car will not be a daily driver, it will be changed each 1.5 years or 10K miles whichever is closer.