The domes will not give you different channels on 2 receivers with dish network, and will not give any HD with direct ever.
We have a dome which works good if no tree's, but only 1 receiver, share one channel with 2 TV's.
Our external 3 lnb antenna works good and would run 2 recievers if we had them.
Winegaurd has a roofmount 3 lnb automatic open dish, around $1300. It's on my wish list, and will give all channels, multiple TV's, even runs the dish hopper. But you can't use it while moving, the wind would rip it right off the roof!