Any load that will stop an intruder will penetrate walls, to a greater or lesser extent. Your priorities are to make sure that all pellets are on target, and to immediately stop the intruder.
In order to be effective against humans the pellets must be able to penetrate deeply enough to reach the vital organs. Unfortunately, birdshot will not do that and is an extremely poor choice for HD (especially 20g). For 12g, only 00 and 1B are considered reliably effective.
I had been using LE132 00 (lower velocity, lower recoil, 9-pellet, FliteControl) for the past few years, even though I always considered #1 buck better. Unfortunately, I was never able to find any #1 that patterned worth a damn. Recently, however, LE132 1B (15-pellet, FliteControl was introduced and it has become my HD load of choice. The patterns are just as good as with LE132 00.
Here is a brief on shotgun HD ammunition by the Firearms Tactical Institute: