Hmmmmm. Low tension nylon strings tend towards mellowness rather than brightness - that's something you would normally associate with high tension strings. My go-to brand for classical strings is La Bella but I use their medium to high tension sets.

Perhaps try a set of their 2001 series? Either low or medium?
I think that it is a safe bet that you will not achieve the brightness you want with low tension strings. 
My God, it's full of stars!
Thanks for the input guys. I guess I'm now going towards medium tension. I couldn't find many low tension strings anyways.

The reason I'm going for medium (and wanted low originally) is cause right now i got high tension strings from GHS and so far I'm not diggin em. They don't fit with whatever I play on the classical. Mind you I usually play rather lead styles with picks. Or may be some finger picking but not classical and not flamenco style either. No fingernails either, hence why I'd want a little brightness from the strings.