The best way to combine the H/V outputs is to use a 2 x 4 (or 3 x 4) DirecTV multiswitch. You hook H up to 18V and V up to 13V and you're good to go with four outputs
Dual shield should work well, as long as its RG-6. Quad might be needed if you're particularly close to a major airport or military facility.
I don't think Slidell airport or the National Guard base over here is going to bother me, although they must be doing explosives training because there have been big BOOMS the past couple days.....
I asked about the coax because I think I can put my hands of a roll of rg-6 dual shield for free....the multiswitch, well next time I see a D* truck I'll tell them mine died and I need a new multiswitch....
Will the Multiswitch interfere with the diseq (sp) switch were I to install it? My intentions are to add a Dish 500 ( if I can find one) JUST for the music choice channels, I miss those since D* got XM.