I think it is smart to have such a resource available, because these are things that many would want to start off their hack with anyways because another video game is a very likely theme people would strive for. Even for experienced users, this can still be an extremely time-saving way to start a new SMW hack.
I don't think, as a normal user, a section right now makes a lot of sense because those starter packs have not accumulated, but definitely a compilation thread somewhere, maintaining a list of links in the OP, would be a great way to kick it off. See how it performs, and see how it grows. I am *thinking* Resources & Tool Releases is a good fit for it.
If you have a Megaman base ROM too (it's a good example,) I think it would be valuable to include a readme that tells which ExGFX file is what, and a screenshot for clarification when a name isn't enough for someone to know off-hand. An HTML readme would provide the perfect way to format this. If music is added, the .msc file and the way it reports to Lunar Magic should suffice, though it is important the text of the file has the whole name of the game and song title for ease of use.
Also, I think that if a base ROM database of any sort is to exist, then because people submit new resources all the time to the site that fit themes like Megaman, it would be wise if the base ROM maintenance were considered a community-wide thing rather than just the choice of the creator, giving everyone an opportunity to propose and evaluate each update to ensure it is quality and kept modern.
Just look above you...
If it's something that can be stopped, then just try to stop it!