Truckie, since you have the paddles, you will already have a button compatible wheel controller slip ring etc, so its alot easier for you to upgrade. Having said that dealers charge £90 per button panel which is f***ing ridiculous, the only other option is to by the buttons seperately.
They basically never come up on ebay in the UK, and so your best bet is German ebay, where you might get some for around 40-50Euros, although i keep an eye out and all the recent ones have gone for 75-90 Euros plus around 10-15 Euros postage from Germany.
One thing to consider is there are also 2 different types of button ones for before MY06 and a different set for after, with your ED30 and RNS you really want the later, as the earlier buttons can apparently have issues with the RNS unit, and will look odd in your motor.
The newer buttons only have a single phone button, and each button is a seperate piece of plastic, where as the older ones are under a single rubber molding, and have two phone buttons one to pick up and one to hang up.
HTH