I have about 2 gallons of Green AF in the garage, it takes very little to run it through the machine. I would imagine any anti-freeze would work.
It's not a cat pump, not sure who makes the pump. If I had the machine here I would check the pump brand, I lent it to one of my guys.
The pump is a direct drive pump, not belt driven. 30wt non detergent oil was suggested when I bought the machine 15 years back, vs. a more expensive re-labeled pump oil. The only problems I had with it was the Honda tank rusted out, and last year the carb let go. It was more cost effective to buy a new carb than play around rebuilding the old one. As far as the gas tank goes. I welded a bracket to the handles used for pushing the machine around, and attached a tank there. The Honda gas tank was too much money!