Im in a similar position to yourself (although I could loose some weight
)
I found that when you do all the W&B on smaller aircraft you either become norman no mates or can only travel very short distances without luggage.
So I invested in a C182 - great size and weigth carrying capabilities. I would suggest you look into group ownership if you are going to do lots of flying and need access to a larger aircraft.
Bear in mind that when you hire a larger plane it often travels faster and thus uses less actual time potentially, small change I know - but can make a difference on longer journeys.
Sorry - I dont know of any cheaper way of doing it . But if you find out let me know...