8PST switches, do they exist? (not 8SPST DIP Switch)
Figure 1. Various "wafer" rotary switches."

The common forms of these wafer rotary switches have 30&deg; detents and one or more "wipers" contacts which switch between the twelve contacts. The wipers and contacts can be arranged in 


12-way, 1-pole
6-way, 2-pole
4-way, 3-pole
3-way, 4-pole
2-way, 6-pole


Usually a stop ring can be added to restrict the number of switchable positions. Wafers can be stacked if more poles are required.

For your application two 2-way, 6-pole wafers should suffice as you only require eight poles.