If you are going to offer this service to customers in the united states I highly recommend hiring a lawyer to review your plans.
Sending money, Virtual Currencies, VCCs and other financial things are HIGHLY regulated.
I was looking into doing something of this nature and was told I needed to register as a money sender business which was something to the tune of $100,000 to register in every state in the U.S.
If it turns out you don't need this, i wish you the best of luck, i'm sure there is a lot of people who would use this service.