This may be old, but today- as in this timeline - they don't make the 1230 or the 369EN/FN stuff so you'd have to make your own...
What Leapfrog gave you is your bible - follow the parts count and values - but when it comes to the "self-bias" part, you're left on your own...
You can make them yourself...
OR just populate the board like the Galaxy kids used to...they use IRF520 and they did pairs. You don't have to follow that so just choose one of the two for your finals and build from it.
Now...they used Zeners to help, the purpose of them was to "crowbar" (Read REGULATE) as well as rectify - yes, they will rectify. But since you're using a 55V, a typical Zener of the 5.6V onto a 7.5V values of 1-watt and some CONSIDERABLY lower values for your resistance can be used to help with drive.
Figure on 4.7K (not 47K) and 10K (not 100K) if you wish to do a "single" final design. These resistor values are not cast in stone so use what you wish but don't go overboard on too low of values...