Here is a modified EN4 CEP2 version (not the PRC version), with the PRC added afterward with the module updater. It may lose a some functionality from the original EN4 PRC version, but since that version is so dated I doubt it works with the current PRC anyway.
It's been a long time since I messed with this, so I don't know precisely everything I changed. The main point of this revision was to make EN4 more of a "low magic" module, including completely removing some item constant effects I thought were way unbalanced: haste and trueseeing. Pretty much all items are a lot weaker on top of this, so don't count on finding a +1 weapon at the start of the game. Luckily, since all enemies also use the same code for their item loot, they are consequently more poorly equipped as well. I think this makes stuff like samurai, soulknife, magic buffs, etc a lot more useful.
Besides that, all spawns are based on the party size of the player entering each area. This means that the module is intended to be played either singleplayer or multiplayer with the one party setting. The custom AI already included in the module is tweaked a bit, although I really don't remember how or why. I added calls to doing "something" with traps and doors on each area enter, whatever that entails, but the call is made to the original EN4 code. It seems it was just... never referenced in the normal version. And one annoying thing should be fixed from the original EN4: corpses don't instantly vanish, they actually hang around for awhile (forever?). There's other various things, like the removal of the quest point system (my precious item balance!), possible weirdness tweaking alignments for stuff, increased XP/gold quest rewards from using skills like intimidate, and uh.. maybe some other stuff.
Since I only recently "remade" this module by diffing the scripts and importing, there may be broken stuff. While I did systematically examine all of the altered scripts, there's a chance I somehow messed something up.
One thing to consider, and it's something I'm thinking about, is using en4_mobdeath.nss to replace the EN4 XP script (that's where it is located at) with the PRC XP stuff. Haven't bothered to do it yet, though.
It uses the currently released version of the PRC, which I think is 3.5 beta 2?
I've included the altered scripts from the original EN4 CEP2 version you can get from the nwvault. I've also included the module before the PRC is added, in case the current version breaks with some future PRC release.
Since the filesize restriction is 500 kb, I've hosted these on hotfile, so I wouldn't count on these links existing for long. I did attach the altered scripts, so with modpacker and the original EN4, this module can be recreated even if the hotfile link goes down.
PRC versionNo PRC Version