Right First things first, Bring the car straight for a diagnostics check, Few traders on the site do this, It will show up any problems that may be hidden, Secondly only run car on Maxol E5, Turbo timer is not nesessary, Allot of people will say a waste of time as all you have too do is let the car idle for 15seconds too twenty seconds before switching off, Dump valve not necessary unless you plan on modifing the car with lots of power.
Mapping, yes most will advise a map for the car as it will reduce the V.O.D (Valley of Death) (Type into search and you will find out) and it will prevent the car from detonation keep your mind at ease,More people will be along and explain mapping better. if you do not wish too map the car then get a knock sensor Bout 150.
Get a good service done, Change all fluids, Belts if they need it, Plugs, ask Any of the traders on here and they will sort you out,
Best of luck and ask all the questions in the world

John