I agree that the JTR book gives only very basic info, but it still was enough for me to decide what I wanted to do.
For example, the JTR book mentions the T56 tranny only briefly, but it does talk about the other trannies, their bellhousing patterns, flywheels, starters, and dimensions. This sets the stage of what things you need to study on your own to see if a T56 will fit. Same with coilovers, bumpsteer, etc. I think the book is great because it makes you ask questions, then you do a websearch, and you end up here!
I have only seen the John's Cars website but I did not like the Scarab positioning of the engine.
Get the book,plan it out first, then buy the kit or just the pieces you need.
Owen