I think if the car looks good, seems 'together' , and has been looked after, then mileage isn't really an issue, the FMBSH up to 160k is a real plus, if it really is right up to date, as it certainly gives the impression that money hasn't really been a worry with the maintenance of the car, as usually when cars get to that age its not really worth paying the stealership prices to keep the book stamped and people seek out the indys.
My 230ce was on 130k+ when i bought it, and my father runs around in a 300te approaching 200k, both have been well looked after and cared for. The black and grey colour combination can be a bit dull IMO, but its what you like that counts. I bought a white car , even though no one else likes them , because i thought it looks nice.
Do bear in mind what Janner said about the 300 / 320 / 300 -24 being speedier, if thats what you want you need a six cylinder. But if your happy to cruise, and still look cool then save a bit on petrol and insurance and take the 220 / 230 route. As i said in an earlier post, the 230's no slouch but you wouldn't want to take it to Santa Pod !!!!
Good Luck