You say you currently have Site Sculpter, do you happen to have SecurityAssist or DataAssist? If you had those or better yet, Dynamic Suite. You'd have all the tools to easily do the steps Jason outlined without a lot of extra work on your part. If you have access to cPanel then you most likely have free/easy access to phpMyAdmin which you'll need regardless of what software you go with to add the columns you require.
Using these same tools, I recently created exactly what you are wanting in less than an hour and pretty much with simple click and fill in the blank steps all the way through.
I don't work for WebAssist but have used their extensions for many years and for what you are wanting to do, those are the ones you'll need.