There's a couple of diffferent ones on E-Bay right now I believe starting around $20. Potomac is good but not cheap. You should be able to find one in any junkyard they are either in the trunk encased in a foam rubber block in the corner of the spare tire well or under the rear seat on the passenger side. What's the part number, or what does the electrical connector look like I'll probably hit the boneyard this week and I'll see what I can find. Let me know what the most you're willing to pay so if I see one I'll get it for you for just the cost. Can't be more than $5 shipping it? I'm near Boston.
P. S. This unit creates suction not pressure so I don't know if the tire pump modification will work out!