I'm using Direcway, and have been for months. Yes, customer support isn't good, but with a little luck you'll not have to call too often - I haven't.
Get the DW6000 - don't even think about the others. Mine is plugged directly into my wireless access point, and I'm typing this on a WiFi laptop in the TV room.
You won't be able to share the dish - at least not easily. They have several different satellites, so you don't know which one you'll be assigned to. I'm on 95W. Could I MacGyver something together for 110/119 - maybe, but why bother?
As for performance, dial-up in my area is 26K at best - typical for rural phone lines due to multiplexing because of the limited amount of copper available. Anyway, as you know, 26K is unusable for all intents - you'll be much happier with Direcway even with the latency. Ping times will never be less than 5-600ms, but that's OK. I use remote desktop a lot, and it's slow, but usable. VPN might give some grief, but if you can get some cooperation from your network people, should run.
Finally, it's very reliable - as long as you sweep the snow off the dish when it gets deep.
P.S. Whereabouts are you? I'm 10 miles from the dead center of Colorado.