I'm guessing you'll keep track of what items they have via clientr.flags or maybe even in an SQL db, you'd run a query based on that information on retrieve those rows.
Then just store the row data in clientr.flags. I.e. clientr.itemdata.(@uniqueitemid) = rowdata;
There's 4 tutorials listed here that may help for the communicating back and forth if you need to:
http://public.zodiacdev.com/index.ph...er_Interaction