While I am fairly sure that Portato does not have the etc-update functionality built in like Kuroo (yet), I would advise you to go with Portato (another GUI package manager front-end for portage). It is actively developed/maintained and it is just a less buggy program overall, plus the developer Necoro is a Sabayon Linux user. He posts in the forums here all the time, so quick easy answers, updates, complaints are possible.
I also advise you to use portage without the GUI front-end for a few small and innocuous emerges, this will help in the long run if/when you emerge something that b0rks your system.
Anything that pertains to Portage