If you do turbocharge it, make sure you buy a new crank, rods, pistons, block, head, cams, fasteners, gaskets, water pumps, oil pumps, radiators (oil and water) and so on to make sure the change is reliable and working properly.
A decent one-off conversion (even from a 'kit') should only cost around $25,000 (plus the cost of the kit). Anything less and you've probably done it badly. And it'll probably be unreliable.
Or, take a turbocharged engine from another car, and swap the whole engine over with turbos, radiators, ECUs etc.
Do not just bolt on the biggest turbo you can find - matching turbos to engines is a science and an art. It is not just choosing any old turbo and fitting it, but spending weeks doing maths to find out the required parameters of the turbo.
But then some people just want to rice their car. And they are too stupid to do maths.