Used Vac Ovens?

So im picking up my own Mr.Extractor tomorrow I believe. Ive been training on one for a bit now and using the owners vac oven as well. Well its about time to get everything of my own and split ways when it comes to extractions. Ill be going to a facility that a buddie of mine Is building and doing everything there. I have the closed loop system and can borrow a pump and basic chamber but not an oven. Im needing an oven pretty bad and pretty quick and funds are getting cheap. For now im thinking of just buying a used or refurbed vac oven until I can save the money for a new one. Does anyone know of any good sites or forums that maybe I could start with? Yes ive looked on ebay and on FB groups. Also I heard the other day that you shouldn't use 2 stage pumps with ovens....is there validity to this? Im located in Oregon if anyone on here happens to have one they are looking to sell.

Thanks a ton guy RIU Crew!