Hi Rob, looking at the pics, the linkages change the travel by moving teh shock mounting point - the one on the left will give 190mm of travel and the 203mm. Whichever link is used, the shock will remain the same.
Looking at the picture posted by Josh, it is going to run a much larger shock that 190mm, especially if it is an 04(ish) era bike. By this point the likes of the Big Hit was running a 200+mm shock with a longish shock.
Having just done a quick google search, Josh was right - the shock appears to be a 222mm eye to eye. Can't find much about the stroke length.
It may be worth a call to Scott UK or a local Scott dealer to see if they can help.
With either mount, you'll be fine with Shivers (I loved mine on my Big Hit - a tad flexy, but super plush and take a real beating. The fork guards are cool as well...I stickered mine up with all of the brands I had on my bike for a 'factory' look.....).