Get the car well sorted in running gear,brakes,suspension,tyres and driver tuition before spending out on turbo upgrades. The money spent on sorting the car out to be as good as it can be as a standard example will far outweigh the instant power increase that a turbo will give and without the stresses and strains that the extra power will impose on the car.
The company in question has great feedback and will advise you on the sort of money that a proper turbo upgrade will cost to make it all work reliably. Good luck with your project