You will need an overhead projector, and some light bulbs of type EVD - 36V, 400W.
For my overhead projector, I found a 3M 9800 series on eBay for $25 with shipping. I highly recommend this model as it has one of the highest lumen outputs making the image extremely bright. It is also designed to be user-serviceable from top to bottom, so if you ever have any problems, it's relatively easy to make the repairs yourself.
For the light bulbs, I googled around a bit and found the best deal on the EVD - 36V, 400W here
. I don't have any affiliation with this site, but I recommend them for low prices and speedy delivery.