I don't think the boat you are looking for exists

Hobie 16 would IMHO be the best choice if you sail solo - you can right it by yourself, setup is quick and easy, and it will be plenty fast. But since you are 250lbs adding a couple of adults will really slow it down and there is a limit to carrying capacity as well.
Tandem Island only fits 2 people and speed is pretty limited.
Hobie 18 would be a better choice for multiple people, however single handing is challenging, especially if you are just starting out. You will need a righting aid, and setup / stepping the mast is not easy solo either. But with this boat you have lots of room to learn...
Hobie Getaway might be a good compromise giving up a little speed for extra carrying capacity.
Because of the above I have 2 boats - a H16 for solo, and a H18 with company... maybe you should consider that as well
