BASSMIDI Driver worked well for me back in 2011 and 2012 when I was first playing on P99. It's been replaced by
https://officialblackmidi.fandom.com/wiki/OmniMIDI since 2015.
If you're going to use something like this, you might as well replace those soundfonts included with the EverQuest install with something that sounds much better.
The 8mb SBLive! soundfont would be a good starting point with its good mix of higher quality instruments. You can find it if you search for it.
Another soundfont I use is the HQ Orchestral soundfont collection v3.0 at
https://musescore.com/groups/young-c...discuss/172224
You can download XMPlay from
https://support.xmplay.com/files_view.php?file_id=676 and load different soundfonts to see what individual tracks would sound like in the .xmi files.