Sorry, no suggestions for footing. I think it really depends on where your located. Do you have a cheap source of sand?
Sexy, when we built our barn we had 6+ loads of shale brought in and smoothed out, then they layed down a load or two of pit run. Then the guys brought in some kind of pounder, which compacted the pit run and made the runin smooth and level. Its been 3 years and the barns floor is usually as hard as cement (except when its really wet, it gets a tad bit moist but it drains REALLY well). Can you rent a pounder for to compact the pit run before you add the crusher? I'm just thinking back to that time and it just occured to me that they may have also used a roller prior to the slammer....similar to what they use on the highway. Anyways, my point is I think it would help you really settle things.