Getting a client compatible with server files for 4.7.X, 3.X, 2.X or whatever

If I were to download a client to play on a LAN or private server I host on my PC, I'd have to downgrade to whatever server version I'm using.

For example, the 4.7.5 server from these two links:
http://forum.ragezone.com/f588/aion-...7-5-a-1073648/
http://forum.ragezone.com/f587/aion-...erver-1075024/

Both rely on the same set of files apparently.

How and where exactly would I get a downgrade to that version or a full client at that version? Preferably from a host which is not a premium cockblocker (i.e. uploaded etc.)