There is a small hole (like 1mm diameter or so) drilled through the hollow rod (which has the rebound adjusting rod in it) just couple of cm up from the rebound valve. This hole will be covered with that 40mm spacer if you don't drill similar or bigger (like I did) hole to spacer. Probably the hole isn't necessarely needed, but I didn't want to take any chances because there is definitely some reason why original Shiver forks have this small hole (both, Factory and RXV, forks which I have taken to parts have this hole).
Don't remember the overall lenght of the forks, but you can pretty easily measure that by your self. How ever it is quite impossible to use RXV forks as they are in F800GS since upper tubes are much lower in RXV forks - your bash plate would go 'trough the groung' at full compression..
And what comes to stock travels you are correct.