Ohh sorry. Upon re-reading, I see now you mean Order Confirmation emails. Sorry. If it were me, I'd send the Order Confirmation emails from your web platform, and then your hand-keyed orders in NetSuite can use the built in email system. You could modify your Sales Order template for non-web sales to pre-check the "To Be Emailed" checkbox, so when saving a non-web order, a NetSuite order confirmation email is generated.
If you want the emails to be 100% identical, that would probably take some extra effort.