I've been looking for an accountant, and accounting software and kept running up against "what is PayPal" - doing manual accounting is beginning to get tiresome - so I did a quick google search and found
KashFlow Small Business Accounting Software - Mac and Windows (no aff)
I had a couple of presales queries and called them to clarify a few things and their staff were very knowledgeable.
I believe I have found the solution I need...
It might be worth a look.