I'd say it sounds like a job for neither of those things. Apple doesn't exactly make rough-and-tumble outdoorsy, industrial type devices, and netbooks are too cheap to survive in any kind of public real world use. I hear all these people talking about contractors or factory workers using the iPad, and just think back to my days working in a machine shop. Metal shavings and dirty hands are a fast way to a scratched glass screen, or ruined netbook.
Here's something a lot more realistic, although probably a lot more expensive.