Have you looked at www.rima.com?
Last I heard, our US members regarded them rather highly. Don't know if this is still the case...?
As for Memorex-branded CMC - I've had some Memorex CMC MAG. AM3s (16x -R), and while they burned nicely enough with no playback/read back problems to start with, they started to deteriorate after 6 months or so.
Other brands I've used (Infiniti, TDK) have held up a bit better. After similar experiences with Memorex + other MIDs, I'm of the opinion that Memorex don't exactly get the cream of the crop when it comes to discs.
But that's just me.