Well I've tried all this already. The version I get from the client contains the corresponding lua files version in the grf files, so I don't think I need to match it (nevertheless, your link does not get a corresponding version for 20120618 nor 20120714 ^^')
I've already made all the confs as you said (except the packet_db_ver, I'll try this this evening). On the other hand, another client I've got, which is 20120618 too, fit with the server's requirement, I can log in, make a char etc. It should be a problem with the client diffing but I can't find an explanation...
On the other hand, mmo.h, packet_db.txt and packet_ver are correctly configured and/or completed. Some friends of mine told me it should be a lua files problem but I don't understand why it works with the other client and not mine...
EDIT:
Well I've finally been able to obtained a client that seems to fit my choices. I can launch, log in, create a char and start a session with my 2012-06-18 version (actually it was a problem with my diff it seems) and to log in a select a char with my 2012-07-14.
Now I've got two differents problems:
the 2012-07-14 can't go further than the "start" option, once I've choosen a char. Can anybody told me what to put in the db_packet.txt file? I think I'm missing the last entry for this version.
The 2012-06-18 go a bit further, as I can start a session, but I've got the "Rejected from server" message as soon as I come in. If I get a look to the map server, I've got a packet error which say that the packet is not as expected.
On each case, can anybody told me what I should put in packet_ver and packet_db_ver plz? I think I should be allright with that.