I'd go for:
Slayer
2 flag
Slayer
Especially considering the fact that most teams will probably not have played together that much so working together properly in CTF (especially in 1-flag) could become a bit cumbersome.
Okay, that sounds good.
As for what settings to do, if you guys really want MLG, I'll do it. Although there's a lot of people that are going to be unused to it (if they've even played it before). I'd prefer to use Arena settings, but if a different consensus is reached, I'll change it.