I have enclosed my cab on my Bobcat 743 and now I need a heater. Would like to mount it next to me on one side or the other. I have ruled out the 12volt ones. I bought one but will return it, not enough heat for me. Any recommendations that will fit into the area I mentioned. How many BTU's would be needed to keep the cab warm and windows defogged. Am trying to keep the price down. Thanks