Downtime isn't an issue anymore. Had some more connection issues, but they're solved.
The +Backstab DMG modifier can be searched in the top line under
Statistics, next to elemental damage, ratio, delay, etc. To search for the +Backstab skill mod, you have set the Skill Modifier drop-down to Backstab (under
Other Attributes), then (if you just want to search for items with a +Backstab mod), fill a 1 in the textbox next to it.
For example, the following search will locate all items with a +Backstab skill mod, and sort them by HP:
http://eq.knowledgepit.org/wiki/Special ... 1_how=DESC