I love the grey Mk4s. Not sure on the styling but it's not my car, as long as you like it that's all that matters (I'm starting to sound like my dad...)
If you found out exactly what mods you have done to the car we could give you a rough idea of the power output. If it has the original K03 turbo on there you won't have any more than approx 195bhp, if it has the K03s it can give up to around 230bhp with supporting mods. Have a look in the project section for an idea on what needs to be fitted to achieve the power you're chasing