Not familiar with the manufacturer, but very familiar with Hoskinghardwood. Jeff is a good man to deal with if you can get him on the phone...busy guy. Three showrooms in Mass. and a crew of installers and finishers too. He is very familiar with individual manufacturer quality and not just there to shove stuff out the door.
Brazilian Walnut(BW)? Yes very hard hardwood. I haven't really known any professionals to predrill and nail. Just get yourself a good quality finish nailer that uses 15 guage 2" nails. Porter Cable or Senco would be my choice. Definately use a pneumatic flooring nailer or stapler. Otherwise your arm will fall off trying to manually install BW.
Any advise on how to cut this wood (masking tape and face down?)
I wouldn't bother. Just use a good quality sharp, new, carbide tipped blade on the chop saw. 40 teeth should work well. I saw that face down idea somewhere. Lowes video? Once again I've never seen a pro do it that way.