There's been a autodispenser on ebay for a while now. It's located in the northwest and the seller wants $1300 for it, pickup only. I use a meteor seigen and a rollma 52 on a daily basis. I'll get rid of them once there is no more roll paper to dispense.
Re: paper curl... a non-issue once mural sheet is weighted, held down by magnets, masking tape or what have you. Remember, the less material handling, the less likely you'll f%$# it up.