I don't know the first map disc supplier, but satnavdvd.co.uk have been getting terrible reviews. Disc not working, no response to queries, etc,etc.
The big problem that I found was that when I tried a copy disc, (it was a test I did with a copy of my own disc) was that it started to work, then hung. The touch screen froze and there was no was of getting the button to work, so the screen stayed in place and you couldn't get to the satnav disc to get it out...
The Saab offer is fairly expensive, but not too bad when compared with the installation of a similar Kenwood unit in my 9-5. The base unit is around £600, then you have to add the steering wheel control connection, the fascia fitting kit, possibly some ground loop isolators, a DAB aerial, etc. And the fitting. But the Kenwood unit is getting on a bit and there are newer ones out there now.
It says £999 fitted on the Saab website. Is that "plus VAT". And it only says a connection for a rear view camera, not a camera itself...
http://www2.saabparts.com/en-gb/uk/offers/But it includes a traffic subscription.
Here's a picture of the way into the satnav slot, with the eject button that is only accessible when the screen moves forward on its motor. The slot has a door in front of it.