Hacking is a art, whenever you get stuck you figure other ways around the problem. Try it, it's fun!

You can download a list of hosts from clip2 via the web and then use it in your client.

Netscape opens other ports to receive data, so firewalls sometimes have to allow for that, so pick a port like 4070 and see how that goes, or set your client's port to 80 or 8080 and see how that goes (for connecting to known hosts) some known hosts are on 5634 and will also accept web connections via a browser
http://255.255.255.255:5634
as a example
sysops can still mess with you, one I know throttles connections down when he sees too much traffic and figures the guy is using napster or something. he can't be there 24/7 though!
As for this forum not allowing html tags, just put your links in proper form and they will be clickable, OK? (or read a little before you get all upset, RTFM)
Once you have a few hosts, your client should be able to collect more as time goes on, just leave your client on all the time, make sure you are sharing some files cause some clients check for that before allowing you to download.