Deffo get the zed!
5k you will need to be looking at the older models as you say , few bargains out there to be snapped up, being the winter it's a good time to buy
I'd get the massive ones as they are very bright. Might be able to find them a few p cheaper
http://www.ebay.co.uk/itm/2x-White-Error-Free-CANBUS-T10-W5W-501-194-13-SMD-5050-LED-Car-Side-Light-Bulb-/290682682274?pt=UK_CarsParts_Vehicles_CarParts_SM&hash=item43ae09bba2
D block is this what you use? Any problems and how long have they lasted? I've been through two sets now on very short space of time and getting the arch liner out with taking wheel off is a pain in the arse to be doing regularly!
Oh and for 8 grand I managed to get a grey gt model with 30k on the clock last year, mot and new tyres etc
Defiantly haggle if your going to go for that one!