definitely the SCT is the best programmer currently available for the 6.0..
CRAZYFORD, the 6.0's don't use 'chips' like the 7.3 did, you actually reflash the factory PCM w/new parameters (SCT), or add an inline module such as edge,bully dog (not preferred way of doing it, less safe, less power)
i run the XCALII w/custom tunes from eric at innovative diesel, and matt from spartan diesel technologies. it's the only way to go !!
i actually have an extra XCALII if you are interested in it. i paid 459 for it new, but i'd make you a good deal. and you can have eric from ID write you tunes, just tell him what you have and what your goals are and it will store up to 3 custom tunes at once, so you can have for example:
economy tune 60hp
tow tune 80 hp
race tune 100-160hp
these are just for reference, the tuning is totally adjustable.