Well, I'm going to first try just using a standard heavy duty Chieta 4x1 WSD-2041 DisEqC switch (because I have one now). Like this:
microHD receiver >> V-Box X >> SG9120b motor IN >>SG9120b lnb in >> receiver port on 4x1 switch >> LNB1 port on 4x1 switch to >> receiver port 4x8 WNC switch >> 0 khz OFF to both Norsat C-band lnb's.
Then, >>> LNB2 port on 4x1 switch to >>> SL1PLL single KU lnb
I don't see why that wouldn't work since the 4x8 switch is basically just a 22khz tone on/off switch, it seems it should be ok.
This should work, in fact should work without modifying the WNC switch, You can try that later. I have a extra dual port Geo Sat Pro SL2 that you can have for free, just pay ship. PM me if interested.