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
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.