The 800D is all painted (or powder coated), will that matter? There is no raw metal exposed that I am aware of.
It's unlikely you'll zap a component, but it's best to be safe, you wouldn't want to frazzle your new shiny Graphics Card. It's not only the case that can be zapped.
Dude, hope the Rig runs great, and I wanna see your afro:good:
As long as you're not scooting around on the carpet during this, the chances of you frying something are slim. Build it on a non-carpeted floor, or on a table.