Titanium still works with the latest eqemu source... You can restrict expansions via a database variable. There is no reason for you to use older versions of the source, very detrimental and unless you have a very talented background in software development you are not going to be able to get the old source working. The latest source has various vulnerability fixes as well as features the old source does not have.
Since you want a 'classic' server:
here are a few examples of how the expansions variable plays in the titanium client:
http://wiki.eqemulator.org/i?M=Wiki&...sions_Variable
Old forum post about it:
http://www.eqemulator.org/forums/showthread.php?t=38826
you can also disabling certain zones by setting the 'zone' table entry minstatus to higher than what players are given. Eg. admin is usually 200 or higher.