I thought about putting the pin switches at the back of the door jamb, down low, in that flat part that the door sits against. the wiring would actually run under the cab.
the s10 wiring I use has these plastic door pin switches that are two wire, when I tried putting them in the actual jamb the shut angle was too high and they kept breaking. I finally modified them to only stick up just barely so the door wouldnt snap them off. went through a looott of pin switches on that one.
you can get insulated pin switches that are single wire from older european cars, they mount with a screw. I cant find them right off in a quick search but hit up a good independent car stereo/alarm shop and they will probably have them in stock.