With Accenture you will likely be part of a huge Accenture implementation team and maybe be stuck with programming etc. for longer periods of time. You will probably get a chance to develop SAP/Oracle/Java/... skills if you want to.
Little interaction with client..
With PA you will more likely be doing things like defining system requirements, program/project management/administration etc. etc. Not really a tech-job..
More interaction with client.. (trusted advisor)
This assuming you "start from the bottom"..
That's my guess anyway.