Hi I have no photos of my RST on the web - May be I will try to sort some out but mine is not a good example as I built it up my self form a frame one size to small! (It was second hand)
SJSC do use mechanical and hydraulic disks on some models. However they take the view that on a road 'touring' bike they are more of a liability than an asset - one more thing to go wrong.
You can get the RST with the EX box but it is probably not much advantage to you (if you stay on road). With both system wheel removal is VERY easy - no quicker either way. There are two (small) advantages of the external gearbox.
There is sealed cable run all the way to the box which is more weatherproof (more important for MTB).there is no internal gear wire to change (expected to replace this every very 20000km+ !!)
The downside of the external gear unit is heavier and more expensive than the internal gear unit and gear changes are also not meant to be quite so crisp.
Gear ratios are impossible to predict for someone else (to many variable) I can tell you on my RST, I am using 42*16 for commuting (which is perfect for me). For loaded touring I use 42*17 which is still too high.
Cleaning my raven is a joy - VERY quick. It is so quick that I now often remove the BB just to clean behind the chairing just for the hell of it. (Very easy to do with a eccentric BB)