Paul, I agree with the previous comments - if you spend not so much time for it, maybe it's not worth outsourcing it at this point. Consider how much time you'd spend to actually delegate this function (to find an appropriate person/company, train them and then check their work). Also consider possible damage to your customer relationships in case of unprofessional outsourced support. At this stage of your business such damage may be irreparable.
Yet, when your needs grow, I'll be happy to consult you on setting up an outsourced support team. Especially if you need it 24/7, you should consider going offshore (e.g. Eastern Europe), so that the time zone differences allow for uninterrupted 24/7 operations of the American and offshore teams.
You can check out this page for more info
Just ping me, if you have a question.