Is a Volvo sterndrive right for me?

I'm getting close to wrapping up the hull design for my 45 ft power catamaran cruiser and I need to nail down the propulsion system so I can move on.

I've been focusing on a shaft drive arrangement, possibly with CPP's, but after reviewing my design objectives one more time I'm thinking I should give sterndrives one last look. What really got me thinking about it was looking at Volvo's D4/DP package, and how easy it would be to design for and install - the whole package is pretty much plug'n play. I know there are Volvo critics out there (I've been one), but I hear the new D-series common-rail engines are good units.

So would something like a D4/260DP do the job for me? Thoughts?

Here's my design in a nutshell:

LOA - 45 ft
BOA - 16 ft
Hull beam - 2.8 ft
Disp - ~16,000 lbs
Draft - 2 ft

Usage - Personal. Coastal cruising, fishing, part-time liveaboard in SE Alaska and points south (and north).

Desired speed: Top speed 28 kts, fast cruise 22 kts, normal cruise 18 kts, single-engine cruise ~13 kts.

Fuel range: 600 NM at 18 kts

Priorities are on protected running gear, low maintenance, efficiency.

Some of my specific questions:

1. Is this an appropriate application for a duoprop?
2. Are there efficiency penalties or benefits with a sterndrive over a shaft drive?
3. Since I plan to run a good portion of the time on one engine when making slower runs, will I overload that engine or have efficiency issues?
4. Any thoughts on the latest Volvo sterndrives? On the latest engines?
5. Other considerations?

Any thoughts/advice would be most appreciated.