Any 19 ft. runabout should have electric trim and tilt on it so beaching the boat on a sand bar or beach won't be a problem with either type.
Outboards shouldn't be run tilted up very far because it messes up the oil pressure. Most newer four-stroke out boards will sound an alarm (beeping) if you tilt it up too high while running the engine (but this won't effect you beaching it as you'll shut off the engine on approach anyway - just tilt it the rest of the way up after you turn it off). An I/O you can run up nearly all the way if you want, but those tend to draft deeper anyway. You wouldn't want to beach an I/O with it running either because you can get sand in your intake and mess up the engine.
If you're going to do 75% fishing, you might consider something like a Lund Tyee:
Though the Lunds don't really offer any sort of lounge seating. It's all chairs.
The aluminum hull allows you to beach it on rocks or whatever. If you beach a fiberglass boat on anything but sand or weeds, you'll damage the hull.