You guys look like you're a bit low on good old 'hit things' fellows, certainly for a monster party. Perhaps I should go for something in that vein?
Edit: I could strip down a wight's ancillary bonuses to make it CR 1/2 (i.e. LA 0). How would we feel about that?
Medium Undead Humanoid
HD: 1d12 Racial Base (Undead)
Speed: 30ft
Natural Armour +1
Natural Slam Attack (1d4 + energy drain)
Special Attacks: Create spawn, energy drain
Special Qualities: Darkvision (60ft), undead traits
+8 Racial Bonus to Move Silently
Ability Bonuses: +2 Charisma, No Constitution
Create Spawn: Any humanoid slain by the lesser wight's attack becomes a lesser wight in 1d4 rounds. Spawn are under the command of the wight that created them and remain enslaved until death. They possess none of the abilities they had in life. Humanoids slain by a lesser wight of 4HD+ return as normal wights.
Energy Drain: Living creatures hit by a wight’s slam attack gain one negative level. The DC is [10 + lesser wight's Charisma modifier + 1/2 the lesser wight's racial hit dice] for the Fortitude save to remove a negative level. The save DC is Charisma-based. For each such negative level bestowed, the wight gains 5 temporary hit points.
Undead: Undead have no Constitution score, 60ft Darkvision, immunity to all mind-affecting effects, poison, sleep, stunning, paralysis, death or disease effects, are not subject to critical hits, nonlethal damage, ability drain or energy drain, fatigue or exhaustion and are immune to damage to their physical ability scores (Str, Dex and Con) and any effect requiring a Fortitude save that does not work on objects or is harmless. Intelligent dead will heal over time and can be healed by negative energy spells such as inflict wounds. Undead use their Charisma modifier for Concentration checks, are unaffected by raise dead or reincarnation and do not eat, breathe or sleep. On the other hand, if they are reduced to 0 hp they are destroyed instantly. Undead are subject to Turning.
I've stripped down the racial hit dice and most of the ability and natural armour bonus, but kept in the attacks that essentially define it as a wight. It should be weak enough for play as a LA 0 character.
The question I'd like you as GM to determine now is whether I will be using the Undead racial Hit Die (d12) when I level up (like a Lich does), or the class HD. This is fairly important for me to know, given that if I ever hit 0 hp I will be destroyed instantly with no chance of being raised short of a
limited wish. I'd quite like to have the more forgiving hit dice, but I'll understand if you rule it's class-based instead.