Although I have not received much feedback, since I've already tested the native toolchain on MSS II and HP MV2120, I decided to promote binutils/gcc to the optware/cs06q3armel feed. This is still alpha testing (use it at your own risk), but much easier to install.
This new feed is athttp://ipkg.nslu2-linux.org/feeds/optware/cs06q3armel/cross/unstable/
You can add this feed with either /opt/etc/ipkg.conf or /opt/etc/ipkg/some.conf file.
There is a known problem of optware gcc ipkg installing two files outside of /opt
This problem is not easy to solve, so I'll just leave it like that.
The gcc package probably can be more granular, but I'm too lazy.