QUICKBOOKS: to buy software or pay per month online?

Running a small electrician's business and self employed with helper from time to time. Looking for software that will keep track of expenses, invoices to clients, taxes, vendor's statements & etc. I'm on the road most of time and have very little time to do my own but can find someone to do it for me like a virtual assistant or bookkeeper? I'd love to be able to have access to my vendor's price list and invoices to my clients from my cell phone. Would love something to use my cell phone to have access to my overall activities. If I buy the program would I have that option or would I have to sign up for an online account & pay a monthly fee? What advice can you give me?