Yeah the custom foam solutions are great but soooo expensive. I have a couple of tool boxes which I then purchased some foam blocks.
One is a standard fold out toolbox, the top two shelves hold standard infantry - Dire Avengers, Fire dragons, scorpions etc. I just cut out cubes so they all stand upright. The bottom section can hold two layers, so it fits upto 4 eldar skimmers and two war walkers. These were a bit tricky to cut out as you needed to leave a good amount of foam on the bottom, if I was going to do it again, I'd by a think pice to just slot in between.
I have another plastic tool kit, the top has a bunch of retangular cups, so just some foam for lining around them and, they work well for jetbikes. I can also remove some of the cups and fit in a wraightlord on it's side. The top of this toolkit slides back and has a good depth, so it can fit Eldar flyers.
These do the job, but to be honest its a pain carrying multiple boxes around. The custom sets can be rather large but honestly I think it is better to carry one box. I have seen some people buy the custom foam and then drop it into standard plastic boxes you can get from the hardware store or $2 shop.