I went for a Bos stoy which I had converted and is now fitted to the SS. I would go for a Cane Creek this time around. Cheaper and apparently better and comes in the right size. At the time I bought the Stoy there was no support for the CCDB in the UK should things go wrong.
The problem with the RP23 is that it blows through it's travel at the sign of a twig in the trail so bottoms out constantly despite putting the correct amount of air in. It also behaves in an interesting manner when braking over rough ground. IMHO it just doesn't suit the Tracer.
If I were you though just see how you get on with it before you splash more cash. These things are not cheap.