As a DM, I personally disallow evil PCs.
Two reasons:
1) I like to run a campaign where the PCs are heroes. There\'s enough evil shit in the real world to occupy my mind, that I don\'t want to have to deal with it in fantasy land as well. Besides, I never saw what fun it is to burn villages and kill the locals when it\'s the bad guys hiding in the hills that have all the good treasure and XP value anyway.
2) Unless you\'re talking about a one-shot adventure, it just doesn\'t work in a \"band of adventurers\" type of setup. Being evil, and therefore greedy for money, power, etc., everyone is often too busy trying to gain the upper hand and backstab the other PCs to cooperate on any serious level. If you like playing games against each other, then I suppose evil PCs might be for you, but otherwise, I\'d say skip it.
As far as modules for said evil PCs go, bad idea in my opinion. See point 2 above for my reasoning as to why having a well-drawn out plot for the PCs to \"follow\" is about as useful as a screen door on a submarine.
And besides, from what I\'ve seen both on this forum and from friends and personal experience, most DMs don\'t really get into modules. I know my thinking tended towards: \"Do I spend this money on a module that\'s one use only, or a supplement that everyone in the group can use over and over?\" Kinda like buying a potion of healing when there\'s a fully charged wand of healing with the same price sitting next to it.
I don\'t mean to sound demeaning, but you were looking for input. When I see an adventure designed for the PCs to be the \"bad guys\" I basically go

and move along.