Considering you'll have three other companions to join you, it doesn't really matter. What I usually do is create all 4 characters at once, some might be Origin story and some may not. To do this, follow this guide:
http://divinityoriginalsin2.wiki.fextralife.com/FAQAnd yes, you can still hear voice lines from your MC (and all of them, if you hand-crafted the companions). My currently party is composed of The Red Prince, Beast, Ifan ben-Mezd and a custom Elf.