Wayne at Bolder Cables tops my list - replaced a used IC that failed the continuity test, with a new one, before I even shipped the flawed one back to him. Always responsive to questions, even the ones that cannot possibly lead to profit on his part - great, friendly source of information.
I would also recommend Take Five Audio in Canada, for parts purchases, they were fast to respond, and great to work with.
I would also like to commend Teac Canada, for helping me, with all my silly questions about the A-L700P before I bought two of them. Their Canuck Service Manager was really friendly and responsive, especially when he found out why I wanted a couple of these.
Mark in Canada