E90/91 335s don't come with xenons as standard. All 335s had sports suspension though, regardless of whether SE or M Sport IIRC.
All six cyl cars have chrome kidney grilles, cruise control and auto headlights as standard; the 330 and 335 have headlamp wash and no cost metallic paint also.
I'm less sure about the E92 coupes but believe all have xenons regardless of engine size and the six cyl cars got electric seats. Later cars got leather as standard too.
If you're after a saloon... There is a white LCI E90 335i for sale at the moment on a 59 plate for 16450 I think it's on auto trader. May get it for just under 16 with a haggle. It's done 89k though.
As for are they bulletproof: Get a BMW warranty for 400ish a year...
Current: E92 335i
Previous: E61 550i, E90 335i, E87 130i, E87 118d, Z4M, Z4 3.0i SMG, E46 330D, Z3M, Z3 3.0i, Z3 3.0i (US)