Firstly I would canvas the locals as to what they want.
Is there a Tesco nearby etc...Depends on how much work you wan't to throw at the shop. You could go independent and buy everything from Costco ( I have head office contacts

) and spend ages on Costs/profit calculations versus competitors.
This could be a benefit for the TESCNO brigade, local shop for local people business, maybe bring in some local suppliers/producers. Free range eggs, store baked speciality bread etc.. What would Hugh Fearnley Whittingstall do?
This is then contrasted with the Costcutter franchise model, for example. A lot less hassle for you, but you pay them a fixed % of Turnover as a fee and have to buy all your stock from them. You could just employ staff and let them carry on without your day to day involvement.
Swings, and roundabouts Jord.