ED:
Here in the States I was able to add-on a helicopter rating to my previous fixed wing rating in 32 hours. This was great in terms of cost and I really did feel quite comfortable in the helicopter, however, once I decided to go for my commercial and CFI ratings that wasn't so great because of low hours. I recieved my CFI rating at around 95 hours and it was a real chore getting a job. Finally found one flying with a guy in a Rotorway. I don't know if you plan to go on with helicopters but if you do fly as much as you can afford.
Brian