Not sure yet. I've got half of day 3 done for both the Mage and Fighter majors. I still have to finish the other half and the full day 3s for the other three majors. I haven't had a whole lot of time to work on it lately so it's been slower going than usual. I want to say I hope before the end of May, but we'll see.
Silas is Mage and Orion is Fighter. You will get more opportunities to talk with the character in the same Major as yourself, but you will have opportunities to speak with all the characters regardless of your major so there isn't really a 'best' route per se, you just get different choices and chances depending on who you're spending a lot of time with.