Thanks for the replies guys, I think you've all run into the same problem i have which is just too much choice for my given criteria
Budget wise, anything I add over/above the £8k will come out of new furniture fund which I can't really do at the moment as I'm literally moving house in 3 weeks.
S2000's are awesome cars but I've had 3 so time to try something new
Had a 3L Z4 before also but just didn't gel with it. Gave some brief thought to a Z4 3.0si but didn't enjoy the last Z4 so I'm put off. Boxster is still a consideration but shame the 987 S isn't in budget.
DC5's I still can't get over the fact it's a much older car for the money as some of the other options and the perception that comes with it (I get a car allowance through work, technically most stuff of the age I'm looking at falls foul of the rules but the DC5 is most likely to be looked at I would imagine...)
335i I'm still tempted - there's a manual 1 owner car with full bmw service history for sale which is always a massive plus point, bit of a trek away though if I decide the car isn't for me...
650i still tempting, though the £570 a year tax is hard to stomach, again not much near me annoyingly so cant just have a quick poke around one.