No your data won't be lost. Just be aware that with a 4gb console, you will be prompted for which storage space to use each time. It's a little annoying at first and can't be fixed but you'll get used to it.
Did this solve your problem?
Sorry this didn't help.
Great! Thanks for marking this as the answer.
How satisfied are you with this reply?
Thanks for your feedback, it helps us improve the site.