Well when I first got into the hobby, I did my engine compartment when my engine was out. It is a piece of cake. I think you could easily do it in a weekend or two. I did most of it with hand sanding and a small orbital sander. Worked pretty good. Masked everything off. I went to the local paint store and had them color match the paint for me then put the matched paint in spray cans for me. It is high quality paint with an easy way for the novice to apply it. However, if you want to have it soda blasted, I know a couple outfits here will actually come to your house and blast it there in the drive way. It is enviromentally friendly and the soda disappears with a quick wash up. However, most will have a facility to go to also. I was quoted $750 for the whole car, so I would expect the engine bay would probably be a couple hundred bucks and leaves the metal very smooth. It won't harm glass and if you protect everything else you will probably be just fine. I would go the DYI route, but sometimes the checkbook route is good too.