For how well done your E90 is, I'd stay away from the 46 and pick up a 30 M. Honestly it is one of the most enjoyable cars to own and you can slowly put work in. If you really have to have an E46 then I'd stay away from all MY's except for 05/06 (trust me).
If you're looking for a DD, why not get into a F10 535i? Or even an X3? People might give you shit for it but who cares what the next guy thinks, I'd say they're two nice rides that are understated from factory.