What Hydraulic Oil for Challenger 607 Vacuum Pump?

Hey first time posting here. I run a water tanker in the Bakken hauling off waste water from well sites. I run a Challenger 607 Vacuum Pump on my tanker and I'm wondering what hydraulic oils are acceptable to run and if there are long term negative effects to not using NVE pump oil? Most folks I know used to run that Super Trac stuff from tractor supply. But they stopped carrying it and now they sell the VP racing utility tractor oil as their cheap stuff (31.99)a Traveller premium as their newer more expensive stuff (41.99). I guess I'm wondering if long term I'll do better running the more expensive stuff or not? Are there specific additives in the NVE oil that help deal with the water and salt exhaust that constantly run through my pump?
Also my vacuum pump has a maximum operating temperature of 375° degrees and regularly gets to 300° degrees (depending on the temperature of the water I'm pulling). And this VP Racing stuff is recommended for use in ambient temperatures between 0°-122° Fahrenheit. Any suggestions would be much appreciated, thanks in advance.
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Thanks! I came here in 2014 and then left for a few years but I've been running water for the last three. It's definitely slow but it will pick up soon I bet

 

That's expensive vacuum pump oil. Do you use it in the pumps themselves or do you use them to run the wet kit? Where do you buy it from?

 

Great, that actually helps me out a lot. I didn't know what those meant but now that you bring them up I remember that I see them on the back of hydraulic jugs. So it shouldn't be too hard to look around and find a hydraulic oil that meets that criteria.