Tony is right, be careful who you use and I certainly do not recommend anything from E-bay.
I recommend "Wake up your car" only because I use their maps and have done over 30 cars without problem. All their files are safe, tried and tested. Don't know if there is a dealer down in your part of the country so you need to go to their web-site and have a look. Also, speak to Dave on the numbers shown and he will give you the necessary re-assurance.
For your car, you will get about 20% gain in BHP and torque which in turn will also give you a good economy gain.
Regards
Pete M
Ps. If there are any UKAT administrators reading this, can you do something about the incorrect timings of the posts. They seem to be running an hour ahead of real time. This one is posted at 2247