I've a friend that was going to buy a laptop for his home but he got to thinking that he could use it for his business.  He has a mobile business and finds people either have cash or credit cards but he has no way of accepting the credit cards. 

If he gets laptop with G3 from say Verizon or AT&T  (he is in eastern Iowa near Davenport)  and a USB plug in credit card reader will that work?

How good of a laptop does he need?  I was suggesting that because it might get some rough useage that he might want one with a solid state drive.

Suggestions?