I have to agree with mof .... get an FS2 straight off, there is so little left in common with the original car and it is such a huge step up in performance that its hardly comparable!
Nothing wrong with FS if you can find one in stock at a good price, I've run the FS for the last 2 seasons and would be happy to again in 2011 but I will be building a new car so FS2 it will be