I would go to a BMW dealer and drive a E90 before test driving a ZHP
As far as parts, I thought it was required by law that the manufacturers supply parts for at least 10 years. Also, while I was having my car serviced, the service manager said that BMW was interested in servicing the older cars (like Mercedes does) so he thinks they'll keep making parts for awhile yet. Not sure how much truth there was to that statement....
At any rate, I am having a blast with my new ZHP. I seem to remember liking it more than a E90 I drove a few years ago. I can see myself getting a 2011 335i in 5 years or so though
2005 BMW 330i ZHP 6MT. Built 11-19-04. Bought 4-2012.
Stock: Nav, leather, PDC, Xenon
Added by me: OEM Alarm, OEM heated seats, OEM aux kit, OEM Bluetooth, intravee, M3 strut brace, BMW Performance Intake, Nappa leather arm rest, updated LCM (triple blink, euro hazards, trifecta lighting, 3 stage brakes), temp gauge