I wouldnt recommend using a DPP twin with a DP34 switch. Doesnt seem to last. DPP44 works fine but is pricey. You may just want to swap out your dish for a dish 1000.2. You can get the whole dish usually for less than a DPP44 switch. That way you would have 3 lines to receivers, no power inserter, no ugly switch.
If you go the DP34 route I would suggest using a DP twin or 3 DP duals.