OK, I apologize for butting in and may not be as experienced as you guys are; I have to agree with Jerry and the grounds. It may be possible to have fried 2 starters but I would say it's the battery ground at the frame. The starter should spit the "bendix" out and you should be able to hear that. If that's not happening, you've got a load drop caused by a short to ground. With the headlights dimming or going out like that, I'd be willing to bet it's corrosion either on the block or the frame wherever the main ground is.
