Expecting a home invasion from Sasquatch?
A 2.75" 00 load will do all you need to do, as long as you put the payload where it needs to go. A miss with 15 pellets is no more effective than a miss with 9, followup shots (if needed) will almost certainly be faster with the 2.75" load.
Unless you're a Sasquatch yourself...
lpl
ETA: 00 buck is a perfectly reasonable choice for HD, unless you have over-riding concerns that would indicate a lighter payload would be a better choice. Paper thin walls, neighbors in close proximity, etc are among the sort of concerns I mean.