The other important consideration is how much you need to borrow? If you borrow enough to clear your overdraft, will you be back using the overdraft the next day? Then you will be worrying about a loan and an overdraft.
Also, have you done a projected cash flow for the next 6 -12 months? If the banks gives you a loan today, will you be able to meet the monthly repayments?
Have you considered other options such as entering in to a partnership or getting an investor for you business to faciliate growth?