There is a uk section of this forum with a number of guys running jb4 (myself included).
Juiceduptuning.co.uk is a UK distributor for the jb4 and numerous other products, checkout the website.
You just need to work out whether you have an N54 (twin turbo) or N55 engine (twin power turbo) - 2009 was the year it changed...
2008 E90 335i LCI M Sport / Manual / Black / Red Leather / Avon ZZ5 / VMR710
Mods: JB4 G5 ISO / Wedge Flash / BMS DCI / AR Design DPs / ETS FMIC / Meth Injection / Spec Stage 2+ Clutch / BMS OCC / Cool Carbon Brake Pads / RB PCV Valve / Forge DVs / M3 Control Arms / Bilstein B4s / Eibach Pro Springs / Eisenmann Race Exhaust
Wish List: LSD