Connecting some SX-700's to a back office PC

I've read postings on here talking about connecting these printers to a back office PC.

We are a small social club and have 3 of these tills and 2 printers (2 in use, 1 as a back up), they appear to be daisychained together communicating via serial ports.

Can anyone tell me what is involved in connecting these up to the office PC?
Once connected, can the end of day figures be retreived by the PC?
What capabilities does the software that supports this have?
Where can I obtain the software for this?

Would it be worthwhile upgrading these tills to use ethernet? (if they don't have the hardware already)

I am not in the club at the moment, so can't find out what version of the firmware is running on the tills (will find out later).

On a side note, if at the end of the day, when a Z1 is being printed, if the printer runs out of paper, is there any way of re-printing? (this has happened a couple of times, if I try using buffer print all it tells me is that a Z1 was printed).

Thanks for any help I can get answering these questions.