We recently put the name on our R29 and the transom lettering width proved to be a bit of a struggle.
I initially thought I had all the room in the world and went for 60" wide, but that won't line up evenly because of the cockpit door and the propane locker on the swim step. So I figured I could do 6x48" on the white part (Upper, we have a blue and white boat) but that turns out the be difficult because of various rails and flagpole sockets and what-not. I think I can get it on there (if it every warms up again) but 4x36" inches would be more prudent at that location.
I'd suggest you take a look at the boat and measure it. There were a lot of things I forgot were there on mine.