Advice required on a Foes second hand bike

[Jimmy_H]

I have just started mountain biking and am looking for a good second hand dual suspension bike to do races like the Karoo to Coast and the Sani2C. I have come across a Foes 2008 model with 5 inches of travel. I understand that this is not the most common bike in SA, but a really good bike by the reviews on other web pages. One of my only concerns is that the parts, in particular the Curnutt back shock, is not readily available and should I wish to change it will be a big issue. Then I will be back to square 1 without a bike and down quite a lot of money. Any advice would be much appreciated. Thanks