I don't think you'll find a good one size fits all answer.  The decisions you make are, in large part, a factor of personal choice.  I'd highly recommend getting your hands on the MFDs you might be considering so you can see which ones work best for you.  See which user interface you find the most intuitive, which one has displays that work well for you.  Decide if you want all touch or a mix of touch and button controls.  I would also recommend you consider using a mix of MFDs and iPads.  I recently completed the loop and despite multiple plotters at each helm I found an iPad a great companion device to the MFDs.  

If you're interested in getting engine data displayed on your electronics with Perkins you will need to use something like an Actisense EMU-1 (Ben E's review) or a NoLand RS-11 (Ben E's review).  I would also highly recommend an AIS transceiver, multiple VHF radios and the usual complement of sonar and radar.  

Not sure if you're planning on attending, but I'm speaking at the spring rendezvous in Norfolk next week on marine electronics.  If you're there I'd be happy to talk with you about your setup. 

Ben