Twin diesel help

[fishndog]

Looking for some help in making a decision.    I now own a 27ft sport fisher with twin 225 Yamahas.  I also own a second home on the chesapeake bay.  Both are being sold.  I am considering the purchase of a used sport fishing boat 36' to 45 feet with twin diesels.  Something I can keep in a slip and have no grass to cut.  I am looking for a bit of information on the average costs to maintain twin diesels, an estimated annual cost for slip fees and hull maintenance, and pros/cons on different   brands of diesel engines.

Thank you in advance for any feed back you may provide.