Actually it wouldn't be too hard to fit in our aeroplane at the moment as all the seats, trim and carpet are out which is why I'mtrying to think ahead
But it is not too big a job to remove these bits anyway. But I have a special tool I use, it is called Colin. It is automatic, if I say "we need to change the windscreen", colin goes into Auto and next time I am there, the windscreen has been changed
I can lend it to you if you like?
But seriously to fit the hull antenna wouldn't be a big job, though I believe there has to be 2 co-ax cables run from each antenna to the box. The box could be located in the tail, behind the baggage compartment bulkhead and a serial cable or two run under the carpet to the G500 / another-display-device. The Avidyne seems to have 4 outputs on it.
I like the idea of keeping everything Garmin though, athough the Avidyne system looks pretty good. I think I've used this before in the DA42 and it works well. We already have the GTX330 so is it legal to wire this up to the GTS800 to squirt out ADS-B?
They both retail for $9995 and if you have a friendly Garmin agent then possibly cheaper, though I appreciate that instalation will cost a bit.