School me on the best machine for big hardwood

[Clive S]

I may well be wrong, maybe steppers are perfectly sufficient, but I can now only convince myself of this if I can see them producing similar results to the above youtube link. At the end of the day, if I can't expect that sort of performance, I don't think I can justify investing so much time in a custom build!

Yes bigger more powerful spindles like 3 kw you can use bigger cutters. If you want more motor power then use nema 34 but then you need higher voltage drives (mains voltage type).

The machine like Wal's in my opinion is far more sturdy than the one you linked to. Modern tool paths can out perform with greater speed and less spindle power. Why not have a look at some feed and speed calculators.

using 10mm pitch screws with steppers you can easily get 10mts/min You will be surprised how fast 5mts/min is on a small machine.