Currently, unless you want to use the SX OS (a CFW that revolves around piracy), get Atmosphère-NX. It’s open-source, just requires Fusèe Gelèe, will have coldboot in the future, and also is the only other CFW (so, basically your only option). You will be able to go Online, and there is a low brick chance. However, the SX PRO USB dongle is quite attractive, and I like the idea. It’s ultimately up to you, but the choices are: Atmosphère, or SX PRO.