newt wrote:ahh thats not so bad then, id been hearing horror stories about issues with them blowing up

Any engine that gets fitted with a turbocharger could blow up, regardless whether it has vanos or not. as already stated its the mapping that is key.
some advice for you is not to run before you can walk. Turbo conversions are not cheap and require a lot of fabrication, this means the car will be off the road for ages. Also unless you spend decent money on parts you will end up with an inferior product.
Rather than setting your sights on a turbo conversion have you thought about increasing the displacement of your m50? its easier and a lot cheaper.