I am thinking of buying some co2 equipment off of Craigslist. The guy Is offering 2 regulators 1 is a ma957 not sure the other but is a Milwaukee brand. Also comes with a SMS122 ph controller and 20# co2 tank. Is this a good deal or no? I also have to drive about 2 hours to go get it. I am planning on using it on my 75 gallon aquarium.