I'm looking for a proxy (http) with a specific extension (.org/.edu/etc ) for getting by certain trust relationships....

Would someone have some magic way of finding some because I find scanning ranges of IP for common proxy ports then resolving then checking each individually is very long/tedious/not discreet.
I have looked at some lists on sites such as cyberarmy and the old UGN Security but most aren't available n e more or don't correspond to what I need.

any magic trix??