captiveworks 700s to pvr ?

I was wondering if with the use of a dongle already set up for tv, a captiveworks 700s can be converted and become pvr ready by plugging in the usb from an external hard drive to the dongle or does it have to be an 800 to be pvr ready only.Comment appreciated. thank you.

Need 800s as far as I understand and believe the pvr doesnt work with japan bin files.

Im using nfps on my 700 and have a chance to buy used 800.Should I take save my money or will it work fine (the pvr that is ).