Well you got a hell of a list there....comprised of somewhat different bikes that span a few different generations haha.
Anyway...what are your priorities?
The 2008/2009 zx6r bikes are more or less identical...with the exception of one being brand new...which shouldn't really matter all that much to be honest.
A CBR250RR has the potential to be a PITA and a money pit....especially if buy a lemon, which is fairly easy considering the age (and the integrity of the available dealers in toronto
)
The 7R is a big, old, outdated monster...somehwhat like my water buffalo gixxer 750. It's comfy (somewhat), stable at low and high speed, and makes a surprisingly good commuter. It's heavy, though. Unless you have the physical size and/or experience handling bikes this heavy, I'd suggest you check one out first to make sure you're comfortable with it.