https to https proxy search

I have been charged with finding a reverse proxy for our network that will
do https to the client and https to the backend server as well. I see that
microsoft does http bridging, but i wanted to do it open source for security
and cost effectiveness, but i cant find an open source proxy that will do
this. I've looked into pound, squid, apache, privoxy, and transproxy. Can
anyone suggest a proxy that will do this or should i just go with ISA? Also,
i have to do https backend because of several cisco software packages
installed - it is impractical to rewrite their links and code. Any ideas
would be much appreciated.

Brad