My honest advice would be don't use Powerstore. Since Ray's passing, there will be no further development work on Powerstore or eCart so it will reach end-of-life at some point, and the only support currently available is peer-to-peer. Patrice is more involved in ecommerce than I am, and I know she mentioned a product a while back that she's now using instead of eCart, but I can't remember off the top of my head what it's called - hopefully Patrice will reply!