On the Choice Specs set, you should put Trick instead of Thunderbolt as the primary slash. Honestly, Thunderbolt sucks on Latios. It doesn't hit anything that likes to switch into Latios, and stuff like Jellicent and Gastrodon really hate Psyshock and Draco Meteor anyway. Trick is very useful for Latios since you can cripple things like Blissey, Ferrothorn, etc. all in one move. Latios rarely ever needs the extra coverage other than Draco Meteor/Surf/Psyshock from my experience, so it's a nice thing to have. HP Fire can be useful at times I guess.
just my 2 cents.