I mainly use and a lot of guys use ecs tuning for OEM parts and other gear
And RHD parts i use toby from bmminiparts in the UK oem parts
http://www.ecstuning.com/
http://www.bmminiparts.com/Home.aspx
and also
http://ebmwparts.com/partlocator/ind...?siteid=216397
but you need a US address for this one, excellent prices.