generic tool kit from your favorite supplier. I put together some older craftsman stuff from my home set up to keep on the boat, and a variety of decent hand tools. I even put tethers on some of the gear that I used top sides. Metric and standard sizes. You will find some specific to your boat needs, and you may want to pay a "good" mechanic for a couple of hours to go over your yanmar, trans and stuffing box. For sure, get one who knows YOUR Yanmar, so you are not paying him to learn your engine.
More important is a good meter, I use Fluke and a selection of spares for the Yanmar, fuel/oil filters, belts, injector, alternator, impellers, etc. Oil, ATF, funnels and cleanup stuff.
I used one of the "rust prevent" plastic ammo box toolboxes with a top tray that fit next to the Nav station to be close at hand.
Best of luck and enjoy the new boat.