I have a crawl space & currently have a US Craftmaster lowboy gas hot water heater that fits comfortably in that area. It was made in 1991 & want to replace it. I looked at their site & do not see any gas lowboy heaters for sale anymore. All they have is electric lowboys. I would like a 50 gallon but will settle for a 40 gallon if it is efficient enough. If you have any info on this, it would be greatly appreciated, Thank you, Kenny L