Distributing any of Mojang's work, including the server and any Minecraft file is against Minecraft's TOS and is illegal.
As for Bukkit, their terms is not as strict, however, I still believe that it is also not allowed to distribute their files as well. You can only get their stuff from http://dl.bukkit.org, which sadly does not go back all the way to 1.7.3
Private Mod Note
Rollback Post to RevisionRollBack
MCF Admin for Servers, Support, and Mapping and Modding
The Meaning of Life, the Universe, and Everything.
I'm looking for a 1.7.3 server cause I have gotten the MCNostalgia mod to down grade the game so I need a server to play on to enjoy the game even more so please someone find a server in 1.7.3 so I may play on it.