AS said before its a really easy job, plus if you buy a unit off here, most will have already been updated to the latest firmware so you know the units havent been messed with. Think there are two for sale at the moment, Smudgster whoi has posted above and JPC if you pick one of those up save yourself a couple of £'s and then find someone on here who would be happy to come and help you fit it.
Or get the guide and have a go yourself, its 9 screws and pulling some trim, the scariest part is pulling the vents out, and if you dont turn the ignition on you shouldnt have any airbag issues.
Where are you based would be the next question to see if anyone will volunteer to give you a hand and do some coding?