So now I await the 'confirm or correct' notification....
LOL... I'm just trying to suggest that if you know what you are trying to achieve, you can make your own! Sure a branded soil product may work, but just make sure you know what you are looking for first... No one mix will work well for all trees and conditions; you will want to adjust based on your situation.
There will always be a mass of different suggestions when it comes to soil mixes, but generally you want:
(1) Mostly inorganic - doesn't break down and allows air and water to freely circulate.
(2) Correct piece size. Not too small, like sand, and not to large, like large pebbles. The larger the tree, the larger piece size you can go with. Gauge by the size of your pot and how quickly the soil dries out.
(3) Absorptive material - like calcined clay, pumice, lava - which absorbs water and releases it slowly.
(4) In the case of tropicals, they seem to do better with a little organic in the mix (no more than 25%) but make sure the material is not fine (like potting soil). Use sifted pine bark or rough cut peat.
Most people when they first start in bonsai think they want their soil to look like potting soil. Nothing is worse for a tree in a container.