I don't know that you can get HD on all three TVs, unless you spend a whole lot of money.
With the Dish tailgater and the 211k receiver, you can get HD on your main TV and SD on your other TVs. The 211k has dual outputs, HDMI and coax. The HDMI output connects to your main TV, and the coax output connects to the rest of the camper. This is the setup I am using, and it works fine.
To this, you have to get the 211k receiver. The more common 211z receiver doesn't have the dual outputs.
I've been told you can connect a hard drive to the 211k and get DVR functionality, but I haven't tried this.