I'd go for the low number. The 12" PowerBook had 2-4 week estimated shipping and people started receiving theirs 2 weeks after they were announced.
unless it was BTO (built to order), you'd be better off picking one up from a local Apple reseller if possible. it appears you are in Australia though so that might not be as easy as it is here in the US.
Yeah, I ordered mine from nextbyte.com.au, one of the local applecentres.
I actually ordered a dual 1.25, then woke up next morning and checked news and saw the price drop and higher spec. I was like "Uh." and changed my order