Congrats on your purchase! We too have a 50’ Bene. We had a Caribe10.5 that came with the boat and it was great. Just bought an Achilles aluminum
10.5 with the locker in the front and is ok. Both powered with an indestructible 15 hp 2 Stroke
Yamaha. With only one person on board both were dangerously fast. With two very fast. Three or more might plane depending on size of pax. Go for the biggest Dink and motor
you can handle on the hoist and the beach. We regularly take ten plus mile trips in the dink and something that can take the chop and move expeditiously will serve you well. Being on a larger cruising boat you will be anchoring
further out and the speed and comfort will be appreciated. Would not buy the Achilles again. It is very light and fast but has a pretty flat bottom and is wet and will rattle your brains in a chop. The similar sized AB or Caribe have a much deeper V and ride better albeit a bit more spendy. Hope this helps.