that's tough...but because of the Britons, I always think of that spelling (Britton) as a large group of my hairy, smelly, manly ancestors.. I LOVE the name, but I would avoid that spelling, LOL. I like Brittan...I also like Brittney, because it's like the "cute" spelling of Brittany, you know? Anyway, hope I didn't offend I just had this funny image in my head ^_^ pretty name choices though!!!
I wouldnt go for Brittin cos that changed the meaning and sound of the name. I'd go for Brittan or Britten they sound the same either way. Brittny is a cool spelling too
I voted Brittan with an A because IMO it looks the least like it may be a boys name, besides Brittany/ney of course. I do love the name, no matter how you spell it, very unique, nothing I've ever heard.
I think with a y it looks more feminine