http://www.klima-luft.de/steinicke/KHQ/khq_e.htm
Check this one out.
(Edit: Just noticed the -20 limit - this is probably the list yu looked at!)
What about
:
http://adsabs.harvard.edu/abs/1995RMxAA..31..159M
The seventh list of the Calán-Tololo Survey is presented. It contains information for 100 southern quasars with a B magnitude in the range 16 ≤ B < 19.5; only 20 quasars are brighter than B = 18.