Agree with Eddie. I was going down the route of having the Kenwood for £999. It is a nice unit, had a play with one at Inters and wasn't all that on it, Its the best looking non OEM one on the market IMO, but I just don't like the fact none of the leads are hidden and come out the USB on the front of the unit and doesn't look symmetrical like the OEM ones.
Here's some rough costs of going down the OEM route (just in the process of doing it myself). You can normally pick up the RNS 510 ver C LED for £550 and MDI for £120, so thats £670. Then bluetooth you can pay anything from £160 upwards depending on what you want and if you have high or mid line dash, so call it £200 (can be alot cheaper or more expensive) so thats £870. Going by Eddie's prices in his For Sale thread a canbus depending if your doing it yourself, pre coded or fitted worst case £90.
So a total outlay £960 + fitting which wont be alot depending where you go or do it yourself. You can probably find the parts for cheaper than this but its just a rough guide.
There's several people on here who can do the fitting and supply stuff or point you in the right direction, Eddie, Morty and Golfman to name a few off the top of my head
Hope this helps