Well, c64 games are easy to find because some of them are legal (not sure about Rainbow Arts and due to the legal issues regarding Katakis itself...well...I mean not that Activision would remember but...) - Jeff Minter's are the obvious ones, as well as Gremlin Graphics, Beam Software/Melbourne House, I think a few Thalamus games, and lots of individual games.
But I will say you can find virtually everything you need except the games themselves from www.c64.org - in fact if you look there you'll easily find sites with games on it because it's one massive C64 directory. I don't think it breaks rules to say this because the site isn't exactly unknown to the IDSA and so forth...look at cia.c64.org and you'll see they've already been busy at work, shutting down sites for 'illegal material' on games such as diablo and soldier of fortune...gotta love that fuzzy search. (this is mostly for those who don't actually know where to start looking, I guess)
Another good source on c64 of course is www.lemon64.com although you won't find any games there. I dunno, maybe the links have something. It's good for reviews, though.
As I remember Denaris never scored as highly as Katakis did in Zzap! 64...I think the difference was something like Katakis was a Sizzler or GM, Denaris rated in the 70s. Keep in mind the same team made R-Type, you may wanna try that. Keep in mind R-Type was bad cos' it was rushed...