> 2)  run a caching name server on the NAT box (it runs off a read only
> file system though with a very small MFS for /tmp) and have the internal
> machines point there for DNS.  I think the NetBSD guide talks about how
> to set this up.
>
> 3)  use IP forwarding on the NAT box to forward DNS requests to the real
> servers
>
> 4)  convert the entire internal network to use dhcp although I wonder if
> I'll have issues with NIS.  Can I use dhcp just to get name servers and
> not IP addresses?
>

2 is probably the best option.  It's something I've been meaning to do
for a while.
You can use dhcp with static ip assignments.  Check out configuring
hosts. (host remotename { fixed-address my.ip.ad.dy } )