I'd recommend applying to an MSN program after your BSN. Walden University has an MSN program in Nursing Informatics.
To my knowledge, there are no BSN degrees in Nursing Informatics.
There are Registered Health Information Administrator (RHIA) bachelor degrees if you want to focus on health information management.
You can get into Nursing Informatics by having a degree in it (such as an MSN).
Check out:
http://www.ania.org