I will prefer to try both. Hire a jeep on day 1 rest days hire 2 wheelers so that if u want to explore different places u all can go separately also according to preference. Do visit Arambol
2 wheelers are more fun, but if you wanna go for a 4 wheeler then, go for an open jeep, You can't enjoy the beauty of goa in an closed car. And for good roads visit south goa.
If u want to explore that day in near by locations or some nearby beaches, u must go with 2 wheelers. but if u want to explore old goa or south goa, from ur destination at beaches on north goa, then u must go with 4 wheelers
You can use app-based operators like Drivezy, ZoomCar or ask at your hotel/hostel reception. Bike rentals are available at every property and more fun.