You need the Everquest Titanium Client specifically. It has everything you need to play here (well once you add the P99 patch that is).
If you have any trouble installing Titanium I wrote a pretty thorough guide (with screenshots!) on the wiki:
http://wiki.project1999.com/Everques...allation_Guide.
If you have any trouble finding the Titanium client, might I suggest you seek a bay of pirates. It may sound scary, but if you bring your trusty rapier (or anti-virus program) you have nothing to fear, as almost everyone here has done the same thing.