Conventional wisdom states: Avoid PC Chips, Houston and Alton mainboards. They're all the same company. Maybe I'm too picky. The truth seems to be that skimping on the mainboard just isn't good policy. While the price is undoubtedly attractive, having even one of these cheap mobos hiccup while "doing business" for a business means that you will get a phone call from a unhappy person. If these boxes are for bona fide businesses, the business owner already understands that reliability is everything. He or she knows that quaility is important, and must be paid for.
Building boxes for friends is a somewhat hazardous undertaking. I suggest that you put quality motherboards in these machines. Don't shoot yourself in the foot, you don't want to lose a friend, or a customer right off the bat!