Doom 3 Custom Skins Problem [Sorta Fixed?]

I've been trying to mod up Doom 3 to make it look good. So far, every mod I've used seems to show signs that it's working (whether doing what it's supposed to do or just being plain ol' glitchy). However, I can never get any skins to work. I have my settings on Ultra High (or whatever top setting is, too lazy to look) which is where modders recommend it. Two skin packs interest me, Rsjrv99's Skin Pack and Xios Skin Pack 5.1. If anyone can help me, thanks in advance. Also, for Xios Skin Pack, how exactly can I get rid of certain features? (eg. new gibbing FX, blood FX, demon carcass stay, etc) I can get THOSE to work...just not the skins -.-

Okay, so installing Sikkmod got the skins to work...and it set the quality down to High instead of Ultra. Now I'm confused...at least I got these bloody things working finally.