Head units w/navigation

So I just bough a '07 Octavia II 1.6MPI Elegance estate with a Stream MP3 head unit. It sounds pretty good, but I've really gotten too used to having integrated bluetooth and several gigabytes worth of music on a USB drive. Swapping CDs is even more of a hassle than I remember, and even stuffed into 30-disc "wallets" they're occupying a lot of space.

My original plan was to keep the single-DIN Blaupunkt MP68 I had in my old Citroën Berlingo, but looking over the 2-DIN head units with integrated navigation from Pioneer and the likes I'm more than a little tempted to splurge on a new one and save myself the bother of mounting either my cell phone or the old Garmin on the windscreen and connecting half a mile's worth of cables every time I venture into unknown territory. Besides, the 1-DIN mounting frame and connectors will run me the equivalent of £110 from the dealer anyway. I'm considering the the AVIC-F930BT or the AVIC-F9310BT, but the information on the Pioneer web site indicates that the F9310 is only compatible with post-FL (2009 and onwards) Octavias. Is this actually the case, or will it also fit pre-FL ones like mine? Just how different is the radio mounting on the new ones anyway?