I think that all 146's use the same engines and all Avro RJ70/85/100 use the same engines. ARJ and 146 use slightly different engines.

I heard that customer specific equipment like non-FAA galleys and avionics sometimes make it too much trouble to buy 1 used plane that's different from the rest of the fleet.

I like the ARJ. Sorry to see it get shot down by the economic upheavals after 9/11. Dornier is also a victim. Once the ARJ's get old, I can't think of what my next favorite will be - possibly the A319 or 757 reluctantly.