When Apple unveils the iPhone 6, do you expect these variants?

1) The regular version, which is essentially a blend of the 5c and 5s
2) A larger, 6-inch version named the iPhone Pro

I suspect that are moving to big ones like Samsung and Nexus. But rumors say both that there would small and large version of iPhone.

No.

What most likely will end up being the case is

5s replacing the 4s
6 (4.7") replacing the 5c
6 (5.5") replacing the 5s

There's no 6" iPhone coming.