Yes, I saw those on the other thread. Nice!
I use brad point bits 9/32 and 15/64 for the holes. The sharp point on this type of bit keeps it from "walking" across your wood at inopportune times and screwing things up. Someone else had one of the stepped bits that I think you're referring too, but said he didn't use it for both holes, just to center the larger hole over the smaller one. Don't know much else about it. Sorry.
Welcome to the thread, hope this helps.
SRT