It seems like not many people are using the MetaROUTER feature, given the lack of significant activity on the forum and wiki regarding this topic, so I thought I would share what I did to use isc dhcpd in OpenWRT running in MetaROUTER.
First I installed the MR-PPC image off of the wiki onto an RB1100 board. The image boots OK, but when I try to use opkg to install packages; I get an error about the URL being 404. Put it in a browser, and sure enough it is. There’s not a directory in trunk for mr-ppc.
I browsed around http://downloads.openwrt.org/kamikaze/ but couldn’t find any versions showing an mr-ppc directory.
I tried trunk/ppc44x and trunk/ppc40x but both resulted in a crash of the HOST router when I tried to do anything with opkg list/install
Decided to try http://downloads.openwrt.org/kamikaze/7.07/packages/powerpc/ but unfortunately they have Packages named as “Packages” not “Packages.gz” … a simple issue of downloading the Packages file, the packages I wanted, and making sure only those packages were in the Packages file; gzipping it, and putting them on my web server. Then editing /etc/opkg.conf on the OpenWRT image to point to the directory of the packages & Packages.gz file.
Then, by executing “opkg update” then “opkg install dhcp-server” the isc dhcpd package attempted to install - but it claimed there were no valid architectures.
I then modified the Packages file and changed the “Architecture” line to “mr-ppc”. After running another “opkg update” and “opkg install dhcp-server”, the package installed!
Worried about the compile architecture, I executed the program /usr/sbin/dhcpd and received the online help output of dhcpd!
To complete the configuration I created /etc/dhcpd.conf as desired, and created /etc/dhcpd.leases, then start dhcpd with “dhcpd -cf /etc/dhcpd.conf -lf /etc/dhcpd.leases”. To start on boot, add that line to /etc/rc.local
A SysV init script is left to an exercise to the reader 
Hopefully this is stable… and I hope that these notes help anybody searching for this kind of information in the future.