Odd how the pricing is all over the place from the same providers.
Yes, you can have DSL without a conventional phone. I use that in my office, with a Phonepower device, it is similar in idea to magicjack but plugs directly into the Ethernet, doesn't require a computer.
We had Comcast cable at home and dish "america's top 200" in the rv ($150 / $64.99)
It took some talking to them, but 6 months ago I got a new dish account at home, a hopper and 3 Joeys, cancelled the RV account, and added the RV's vip211k as an additional outlet at home.
It took some talking to get them to do this, I basically just kept calling until the luck of the draw delivered a customer service rep willing to get past "procedure" and corporate rules and make it happen.
We pay $84.99 for the hopper, 3 joeys, 1 "additional outlet" and America's top 250 programing.
When we go fulltime (day cannot come soon enough) I plan to install the hopper and 2 joey's in the motorhome, my bill will go to ~$64.99.
We've never ever had any problems at all with the hopper or joey's. Ours are not owned, they belong to Dish. If it was locking up, they would be replacing it.