SPN Newsletter recs Gen fic, too (clearly labeled, even!): spnnewsletter
SPN community (trying) for episode quality fic: spn_notkansas
SPN community includes slash but is wincest free: spn_brotherlove

I haven't actually hung around in these long enough to vouch for the quality of fic there (mostly I watch for stuff to be rec'd by morgandawn), but it's worth a shot, eh?

PS - The Cameron/clone!Jack likely to hit your age-gap squick from both ends? Take These Broken Wings by synecdochic.