Chris I got mine off eBay. I have not looked recently but they are common there for less than about $1000. In this day and age most of these systems are about the same. You get what you pay for. I liked the Ellipse because it has an add-on Eclipse backup camera and you can plug in a Sirius satellite radio. Not sure what the situation in EU with satellite radio is. All these units come in two height sizes 1 "Din" or 2 "DIN". This is standard across them all. If you pull out the Lamborghini (Audi) radio any 2 DIN height Nav system will fit. The only variable is the depth and there is plenty of room for all in the Gallardo.
As I mention in the article the only "catch" is supporting the unit on its sides. Most car audio shops have "adaptors" to accommodate different NAV/radios/cars. Also look on the web at places like http://www.installer.com/kits/# I made my own – this I am sure is not for everybody. You can also go with 1 DIN height units and put in a CD holder “pocket”. With these units the display pops out and folds up. The Alpine units in my opinion are really good in this group.
I used a non hard disk NAV unit because my experience with HD drives in cars is the vibrations eventually get to them. However they tend to have fewer features and are a little slower.
Yes the connectors are always the same. You will be looking for an Audi SymphonyII adaptor. See the above web site.