[gentoo-user] rpm or deb package installs

[James]

Hello,

So it's been some time for me, but there use to be easy ways 
to install .deb or rpm packages on gentoo; maybe in  /usr/local/portage. [1] 

I only find this guide on wiki.gentoo.org : [2].


So what I really want is a modern (safe) methodical way to quickly install
.deb or rpm packages (many should work) into /usr/local/portage
for quick testing and evaluation before I hack together an 
ebuild for it. So are there any newer (vetted) methods to
do this?  Anyone who does this quit a lot would surely have some
methods if not custom scripts addressing many little pitfalls?
Are rpm's better to install than .deb packages in general? What about 
cleanup and removal: semantics, syntax, or scripts?

I do see these in portage: app-arch/dpkg   and app-arch/rpm.


Any caveats or tricks anyone cares to share? 


James



[1] http://www.gentoo-wiki.info/TIP_install_programs_without_portage

[2] http://wiki.gentoo.org/wiki/RPM