Hi
I recently joined a cessna 172 group and am doing alot more flying that I would renting due to costs my example is 6k share 1/6th 65pm and 66ph wet
The problem you will have is trying to get four adults like you with any amount of fuel to go anywhere without having to keep stopping and filling up !
To give you an idea i just a W&B on my plane with 4 adults at 17 stone on limits with 85 liters of fuel which would give approx 1hr 15mins with 45min reserve no baggage
and maybe quite cramped
Cheers