DFU restore and set up as new phone will leave no trace of the jailbreak, you can then sync again to get your music etc back.
DFU restore and restore from backup can in theory leave traces, as some tweaks work by modifying configuration files that are backed up. If you disable such tweaks, i.e. make your iDevice look as normal as possible before backing up, and then restore it, you will be fine. It may be theoretically possible to detect that it has been jailbroken, but it will require a significant effort, and no-one will bother.