Tons of good info here...
Regarding vehicle carry, in Texas we have Castle Law so even if you don't have a license, the vehicle is an extension of your home and you have a legal right to possess the weapon in your vehicle as long as it is concealed and you may legally own a firearm. However, Austin and Houston (who are very anti-gun) police officers have arrested and/or detained individuals complying with Castle Law. They beat the wrap, but still have to take the ride.
I mounted a kydex style holster in each of my vehicles. My truck has one that fits both my 3" and 4" XD Mod2 9mms, and my wife has one that fits her LC9s. She likes being able to place it in a secured mount inside of the center console when she arrives somewhere restrictive like the girls' schools. I can take pics if you guys want.
Regarding police encounters while carrying on person or in vehicle. I recommend to not use the term Weapon or Gun, a rookie LEO may get excited if he overhears it with low SA. Best to use the word firearm or the actual Manufacturer (I have a Springfield XD9 in my console officer) very calmly. Definitely agree with lights on, windows down, hands visible. The world has changed and these brave men & women are approaching a vehicle that may carry a soccer Mom or may carry an individual who wants to kill them. Nothing Routine about a Routine traffic stop these days.
Back to the original topic, a revolver is not a bad idea, but does limit capacity and not as concealable as a single stack. My brother has an LCR in 380 that he likes but it is very snappy with HD ammo. Definitely a fan of 9mm. Light recoil, cheapest practice ammo besides 22, and ballistics vs a 40 or 45 in self defense rounds are very very comparable. (Lets not start the caliber discussion/arguments fellas!) My 45s are more for range and/or HD. I don't have any firearms that don't have good HD ammo at the ready. Even my 22s have an HD load ready in case its the only thing handy!
One thing to consider for CCW is your state laws regarding printing, accidental display, or open carry. The first two were a much bigger deal here in Texas before Open Carry passed. As long as you are in a holster now, printing is a non issue. And always be in a holster! No waistband gangsta carry... Anyway the local laws may affect how/what you carry. For me it is always OWB, single stack in a T-shirt, double stack in anything more (polo/button up/jacket/etc).
If your wife is going to shoot also, you may end up with two CCWs. My wife has very small hands and we don't find the same gun comfortable, plus she is more sensitive to recoil so that's a factor. Definitely hold every possible choice at a gun store to see if it fits your hand, if able rent or borrow and shoot them before purchase too. I generally find a gun store window shopping session, multiple online reviews, and talking with friends is all I need to buy a gun online. Online guns are almost always cheaper than in person, but you have to do an FFL transfer. No big deal, but weird the first couple of times. Every firearm I own except my skeet shotgun was purchased online.
Speaking of shotguns, make sure your wife is comfortable with it for a HD weapon. My wife is not a fan, so we stick with Handgun as her primary HD plan with a backup of AR15/AK47. I like the HD shotgun though. Hard to miss, but same can be said for a full frame handgun with a laser/light combo. The 22s are for when we run out of everything, just prior to knife fighting! Don't even get me started on knives. This stuff gets expensive quick!!