which brnach?

I tinkered with STABLE a year or so ago, and was able to get what I
wanted (add some apps, remove some,, support for my hardware, etc...).
I've got some time again and wanted to play with this some more.
Looks like a *lot* has changed in the past year.

I'd like to build research, or a derivative, on a gentoo system.  (Can
do chroot, but thought I'd see if it will build on gentoo.)  Tried the
research branch and ran into some trouble configuring perl.  Before
diving in and figuring out what the problem is, I wanted to see what
branch people would suggest?

Thanks,
Rob