Do I need any special power cord or inverter / converter? Change from multi switch to SWM on set up?

I have a SD directv rec in my camper and am using an 18" round Sat to watch SD channels. I am switching to an H24 rec and was wondering with a B Band converter can I use the same Sat and get HD channels? If not what satellite do you recommend and what is the easiest novice set up to get the HD...