The Iron Canyon string box is awesome, as previously mentioned. I don't use a toe stick as the 2 rulers it comes with work well.
I personally find hub stands very useful but not useful enough that I'd pay $900 for them. I use the hub stands to dial everything in then mount the wheels towards the end of the process to validate and finalize. It saved me a ton of time during the process. I also found that the camber measured differently when comparing numbers measured at the hub stands vs the wheels but that is a non-issue once I factor that into the equation. The difference was 0.3 degrees for me. I'm still learning this but this is my experience to date.
I use a Longacre laser level to ensure that all 4 scales are at the same height. I also have Scale Pad Levelers (not these - some cheaper ones) that are used to ensure that the individual pads themselves are level. The scale pad needs to be level when you place the laser level on it to try to get the pads at the same height relative to each other.
Hope that helps.
Which hubstands do you use? I was looking at the ones sold here http://hubstands.com/ which are a lot different than the flying miata ones.