Yes, I am running a 115, an old '84 Johnson V-4, although on a 20' Seafari - probably a little heavier and more windage than your CC. The motor is sound and solid, and with 2 on board and a full tank of gas I top out at 31 mph GPS - like you say, on open ocean I rarely can run it there, but it has a nice comfortable cruise point at 25-27 mph, put it in 2 - 3 ft chop and I'm down to 15 - 18 mph, holds a plane down to about 10 mph - which I have had to do when faced with unexpected 5 - 8' slop - would choose not to repeat that, thank you
If I had an open wallet, I would look at a 135, either an Etec or a Merc Opti - but then I have the 20" transom and original floor height, so motor weight would also be a concern to me. With the mods you're doing, 25" tranny, raising the floor, you won't have those concerns. Given that, a Suzy 140 fourstroke might be a real good choice, also.
On the flip side, there are those who think a 150 minimum is needed for these 20's - I just can't see that, given how mine runs with an old 115.
If I might ask, what hp was the old 77 Johnny you took off, that you thought was more than needed ? Some folks have put up to 225's on these boats - older, lighter two strokes, that would be a screamin machine... on a lake!!
All boils down to you, your preferences, need for speed, intended use, etc.
Bill