I agree, go with the G-27, even if you can't get the $300 one. From a firearms instructor standpoint all functions and controls are the same as your main weapon. Under the stress of the moment, especially if you need to draw your back up, all the other weapons training you have gone through with your G-22 will still apply and you will be able to fight well. Also the mags from your G-22 provide a ready supply of ammo for the BUG.
Regarding your wife, I've been through this myself also, so let me suggest this. Let her decide which guns she feels most comfortable with, then support her choice with all the training and practice you can provide for her. My wife trained with a revolver as one of her first firearms. As many autos as I have and shoot, she is still more comfortable with the revolver, so that's what she has, and there's another at home. Don't make the mistake of trying to impose your love of autos on her if she's not comfortable with them, it could backfire.
Good luck with both!
"Still training Sheepdogs, one puppy at a time."