Reasonable Incorporeal Options for Undead Minions?

[Amphetryon]

By 'reasonable,' I mean choices that aren't going to accidentally create a wightocalypse or otherwise snap the DM's game in half (Allips spring to mind as probably too capable of doing this), and aren't going to be so weak as to be little more than a time-suck to manage during combat. The character in question is a level 12 Necromancer (28 INT, 20 CHA thanks to items) with the Undead Master (http://www.d20pfsrd.com/feats/general-feats/undead-master) feat (if that matters for your consideration), and a strong RP-based preference for Incorporeal Undead.

[Psyren]

Ghost is your best bet as they can match your alignment and not create spawn, but the only RAW way to create one is to be a high-level witch.

Most other incorporeal undead create spawn, so you may just have to resign yourself to ordering them not to do that and/or not strike any killing blows.