Great question! I thought about this as well. For a newer model, I like what the Tartan Fantail has to offer. Giant cockpit, overnight capabilities, carbon mast and self-tacking jib. Of course it comes at a price. Nonetheless, it serves as a good example of the features needed in a daysailer for lots of guests. One feature I would add is an enclosed head.
For a cabin boat, I think the Catalina 350 is a good choice. It might have more than you need down below, but the cockpit is roomy, it’s easy to sail, has the enclosed head and is of the right vintage.
One thing I do not like about the great looking Pearson Commander and Alerion for the specified usage is the tiller. Tillers take up a lot of space in the cockpit and makes hosting guests more difficult. I like tillers, mind you. Just not when the purpose is to have 6 people in the cockpit.
Just my opinion. Definitely a fun topic to consider.
-cf
Craig