We offer an entry level electric power planer that works great for shaping all types of foam and is simple to use.
The Hitachi modified planer is a surfboard specific planer with on the fly depth adjustment, a bit more power, and better dust control. The modified Hitachi makes shaping railbands much easier and allows you to shape your surfboard's foil and rocker fluidly as you can adjust the depth of the cut while walking the board. It is a great tool for the experienced shaper or anyone that plans on shaping a bunch of boards.
You can also use a stock planer like a Bosch, Dewalt, Makita, etc. The planing techniques are different since there is no adjustability but the goal is to remove foam quickly with a planer, which stock planers off the shelf will do. There is just more hand shaping with a G-rasp and Rasputin involved when using a stock power planer.
Another note, if you choose a stock planer make sure it has 2 blades for a smoother cut on foam. A single blade power planer will tear the foam like crazy and make more work for you!