Well if you want to buy new, there's not much to choose from: only the X and MX remain. The tools are the same, the only choice is between one-hand opening of the knife blade (MX) or immediate availability (X). Now if you're willing to buy used (or if you can find old stock) the XC (serrated main blade) is an option. I am partial to the S model, but it doesn't have scissors so it doesn't fit your needs.
There are additional variations with the accompanying pouch and tools ("Plus" sets come with bits and a L-shaped driver or a ratchet) that add to the price. 120$ seems average for a naked Spirit, but it would be a great price for a set.