Pretty much every motorbike battery you will buy is sealed for life, so any decent, modern, bike charger will do the job.
If you use jump leads, only do it for as short a time as possible from another battery as the more discharged the battery, the higher the current and the greater the chances of problems. When jump starting, what you're trying to do is supply enough power to get the other bike started, and to then charge the dead bike's battery from the alternator, not to fill up the dead bike's battery from the other one.