If you use a C182 for example, you need to cover a bunch of compliance topics in order to be legal. You'll need to have an approved operational procedures placard fixed to the panel with things like v speeds and power settings on it, an approved weight and balance for airplane equipped minus interior with 4 jumpers on the floor, and paperwork for the mods like the door, wheel guard and whatever else you put on it. Also you need an approval from the FSDO for jump operations at your airport if it is near controlled airspace. This will include stipulations on when you can jump, where, and other specific details that are determined by the FSDO.

Be that as it may, setting up a drop zone is not a tough task and lots of mom and pop owners do it. No problem flying with a private ticket if you own the business. For reasons Rick mentions it is usually the owner of the operation with only a private ticket because it helps him run the operation more smoothly. DZ owners are usually are just avid divers and they rarely bother with higher certs. Visit a mom and pop drop zone operator in a neighboring county and tell them you want to set one up in your county (not theirs) and they will love to talk about it over a few beers.

There are a lot of old C182 jump planes listed in TradeAPlane or what have you, so you can just buy one for something like $40-60k. C182's are the best option for startup operators. Then all you have to do is find a hangar to operate from. Anything will do for that, but you need something to train people in and to provide a clean floor for repacking, a place to keep papers of course a large beer refrigerator. You may even be able to find a turn key operation for not much more than the cost of an airplane itself. It's a great little business and can easily pay for any amount of weekend skydiving and flying if you are into that.