Back to my "simple solution" theme...
Since you say you don't have room in your GunVault, simply pick a pistol and go with it. If capacity is a concern, that's why extra magazines are on the market. Drop one or two extra loaded magazines in with it and be done. Easy-peasy.
Remember...there is such a thing as over thinking this. The purpose of a gun in a nightstand isn't as your first line of defense...if it is, then you're failing right off the bat. It's part of a holistic approach to your overall home security.
We could discuss what all else constitutes a comprehensive home security plan, but in a nutshell it's a combination of passive and active security measures. Exterior lighting, well trimmed lawn which keeps bad guy hiding places to a minimum, pets, alarm systems, evacuation plan, home phone, cell phone, kids toys scattered all over the place, weapons of opportunity throughout the house (such as sporting equipment like baseball bats, kitchen cutlery, garage tools), and any firearms. Pick and choose amongst these, and other options, as you see fit.
Firearms are a small part of the overall plan. The single most important aspect to having a firearm as part of a comprehensive home security plan is....having a firearm. (Next is being proficient in its use and understanding how to use it for home defense.)
Either choice you have is suitable. Since you say you only have room for 1 on your nightstand, then pick one for whatever reason(s) suit you and go with it.