Well, first of all I would recommend that you read the mailing list
archives... there is quite a bit of talk about getting things like this up and
running, also I am currently working on a faq/walk-through which should be
posted on my site by the end of this week...( www.ecst.csuchico.edu/~tbeede )
perhaps I could intrest you to write up a description of your dealings when
you get though with them so I could add a it to the faq?  However, I would
recommend that you get a few NetBSD utilities, you need to get the most
current versions because even the ones which come with NetBSD-1.5 won't work.
From what I understand you will need the most current version of the config
tool to build the kernel source.  You might need the make tool as well and
perhaps a few others lurking around.  I'm really not exactly sure because I'm
doing my build on a netbsd-current machine.  Here are a few resources which
you might not have found which will hopefully help.

NetBSD cross-compile docuement www.netbsd.org/Docuements/cross
NetBSD change logs www.netbsd.org/Changes

Hopefully this might have helped...
--Tyrel