Don't put oil on the body!!! You'll have a tough time getting it out of the pores prior to painting. How long will the body sit before paint hits it?
If it's just a few days Eastwood sells a product called "Metal Prep" that inhibits flash rust for a couple of weeks. It works really well and requires no clean-up prior to painting.
If it's going to sit for a month or two and the garage is dry you can use an etching primer on it. Sherwin Williams makes a great one - check with your painter to make sure he has no problems with it. He shouldn't.
If it's going to sit for a month or two and the garage is damp, you'll have to spray primer and a sealer coat. Get some ventilation in that garage.
If it's going to sit for more than a few months I'd just wait and perform the chemical stripper closer to the paint date. Hope this helps.
