08 will be cheaper up front, 09 will have better residual on the end - do you want to spend extra now ('09) or later ('08) - i would say its always better to delay extra expenses.
since you're not getting the nav - the 08 and 09 will be very similar (btw sport pack + premium is an excellent choice of options)
as for 335 vs. 135 - there's a price difference, the 1'er will have better performance/feel and classic bmw looks, the e92 will have modern bmw looks (the e90 will get a facelift, i'd definitely wait for that if you want the sedan) and the e92 will have more prestige (for picking up girls, impressing the neighbors, if that's your sort of thing).
check this out for a same day/same driver copmarison of 335 and 135:
http://www.edmunds.com/insideline/do...ticleId=125908
as for room, the 135 has more room than the e92 in certain measurements and vice versa in others.