Re your propellers
When the boat is set up the dealer usually supplies propellers that are suited to the engine boat configuration. It is very unusual to supply props for running in only and then expect the client to buy replacements. I would check this arrangement with the dealer.
There are several aftermarket propellers available to suit your engines. Because they are counter rotating it does limit you a little in choice. Hydromotive propellers are very good but expensive. Any of the Mercury range can be adapted to fit your evinrudes. Also some of the Solas range are available as counter rotating.
What I would suggest is you speak to your dealer again about the props that come with the engine. When you have tried the boat out of a while with different loadings and different conditions you will get an idea about how the props are performing, try and make a note of what engine rpm you get in different conditions before you consider changing the propellers. You don't want to end up buying loads of different sizes. I would have thought that 27" pitch is too high with 14 people on board I would suggest something nearer to 23" or 25" pitch would be better depending on how high the engine is mounted.
Let us know how you get on.