I just used the stuff that came with the Fortec dish.
To strenghen the pallet, I added a whole mess of sheet rock screws to the top and bottom of the pallet. Then where I planned to put the lag bolts to fasten the base down, I added 2x4 / 2x6 / 2x8 scrap underneath the top, fastened by more screws. The more slats on the pallet these reinforcements connect to. the better.
When I want to adjust for azimuth, I just loosen the lag bolts, rotate and retighten. If the base brackets get in the way, I just remove the bolts temporarily. Suppose the fastener bracket was exactly in the way of the base bracket... In that case I can relocate the fastener brackets. There are fillers between the pallet slats with substantial wood underneath to accommodate room to move the fastener brackets.
If it's really wet in your locale, I would be concerned about wood rot and rust. There are fasteners with a screw thread that have three or so prongs that are designed to be driven into wood. Then you have a fastener that you can use a regular bolt with.
If you wanted to get something fancy, you might consider toggle clamps or something like that....
Right now, I use 12 8x8x16 blocks for ballast. That's about 350-450 pounds or so, depending on the weight of the block. In the summer we can get strong winds associated with thunderstorms. There are houses and trees around to break some of the wind, but I can envision the dish flying away given the perfect storm.

!sadroll :river

In the future I plan to use solid block. My target is more like 750 pounds plus.
Looking forward to seeing more of the review.