Check on here. Some cracking cars have gone up for sale. I think 8k is more than enough.
3.0i M54 all the way in my opinion, basically the same running costs as the 2.5 but a bit quicker and sounds better.
Look for-
MSport seats. Preferably electric and heated.
Clean alloys (I'd avoid 108s, they look great but deteriorate like mad)
Roof motor relocation
Xenon lights
Plus obvious things, low mileage, no accidents blah blah.
If someone has gone to the effort of relocating their roof motor, they've probably loved the car. It's those little things that are a giveaway.
Paul.