I would look at the Focusrite Pro40 and Saffire LS56. The LS56 has 2 "liquid Pre's" which model some very desirable "character" preamps, which you may find more versatile than buying a straight interface and adding 1 or 2 expensive "character" preamps(by "character" I refer to preamps that impart something unique to the sound. like vintage NEVE or API preamps do). Both these options also allow for expansion of IO far beyond what any Mbox can handle(Mbox Pro is only capable of 8 inputs total). Not trying to steer you away from Mboxes, just offering food for thought
