To O/P: seriously? Is your business doing that well that you would walk away from what should still be a profitable job without even trying? Aren't you basically leaving money on the table?
While I rather provide the complete package, with business and economy being what it is, I can't afford to walk away from a job just because client provides the equipment.
I manage job expectations; charge for every little thing; don't provide warranty for equipment related issues, and charge for testing (usually at client's location) for every piece of equipment I'm installing.
Does it always end up well, no. Do I always make the money from the job, yes.

Others will tell you that if you start taking that caliber of client, than any referrals will be for that kind of clientele. While I agree with that statement, I believe that it still beats sitting at home not being able to pay the bills.
If on the other hand you're busy and business is booming, than dump the client and don't look back.