I was trying to do ks=http://<host>:<port>/ks.cfg and was a little suprised that it didn't work. I did something else, but here is an (entirely untested) patch to add support for port specification.
Created attachment 101180 [details] Add :port support for http
Looks sane, committed with the compile fix that was needed.
*** Bug 125918 has been marked as a duplicate of this bug. ***