WC3 1.30.1
WC3 connect (also has DDL for wc3)
WC3 connect source (if you don't trust the builds on ent's forum).
You will need to register on wc3connect. You can also do it on ent's website in some particular corner. In WC3 you must set your LAN name to your ent username or it will break the game.
You also need to run Frozen Throne, not Reign of Chaos. You can switch between them on the main menu with a little icon next to "single player".

You don't need to download SWAT map separately, that will happen when you join. If that breaks for any reason I'll arrange to get it to you some other way, I don't think it's listed on swataftermath.com.
Recommend joining mumble at harpy.faith for voice chat.
Game name to join is zergling_man##, generally. I have managed to run a dedi host bot but it's laggy so it's on hold.