If the main goal is to have easy access to NTFS volumes, I don't think a big Linux distro is the best choice.
First, the latest version of pmagic that was already included in UBCD could still be used in future UBCD releases. There is no reason to rush any such change.
The pm2ubcd scripts can still be used by users that have access to any version of pmagic, included older and/or newer ones. IMHO, the scripts could be included (and other similar scripts could be created and added for other distros). Note: Although I was / am involved in the creation of the pm2ubcd scripts, I think I am being objective regarding this matter.
If the time comes that pmagic (in whichever version) is not included in UBCD, the special modules can still be included, or provided here as additional optional downloads, so to easily be merged by users.
If other Linux distros are bundled, it could be useful to consider the ones that not only provide access to NTFS volumes, but that can also take advantage of pmagic modules (or with a slight modification of the package).
If such distro can run in older hardware too, and its size is minimal, those are very important features. If the distro is actively maintained, and with an active forum / community, that's an important plus.
Basically, distros that support some form of "txz" archive and that use "modules" could be potential candidates.
and their respective flavors, modules, derivatives and spin offs.
Adding tutorials in the wiki regarding the modules, or how to merge them with UBCD, would be IMO a better option than bundling any full distro. The user would be able to merge and update whichever distro with whichever optional module.
But, again, I think that keeping pmagic version 2013_08_01 in the next release of UBCD (whenever it comes out) is adequate for now. Please, let's not unnecessarily rush such change.