I say just get it running and drive it. A full restoration will cost $20k-$40k depending on the starting point. I'm about $7k-$8k into my Scrambler and the tub isn't even off yet. I'd hate to ask "el director" what he's got into his Jeep. (Any radiators yet this year? )
The Dana 25 will be fine unless you put larger than stock tires on it or a locker. If you plan on that then find yourself a 76-79 Dana 30 to swap in, you'll get much improved steering, but you'll have to swap other other stuff too. 77-1/2 to 79 will have disc brakes. Watch out for the 77-1/2, it has a different master cylinder than any other year and is impossible to find.
For the rear axle, a good viable upgrade is a pre-76 Dana 44 flanged axle (not a two-piece) I forget which years exactly. 76 and later have a centered differential and won't work with the original transfer case.
If you're lucky and find an overdrive for the transfer case it will go a long way to make it streetable, for tooling around It'll be fine, but there's a reason convoys used to go 45mph on the highway. The gearing winds out the 4 banger pretty quick.
Not that I'd go faster than that with an 80" wheelbase.
My wife *loves* both of my Jeeps (the CJ-7 and a TJ). She wants a 4-door for herself.
Wait until a really nice summer/fall day, pull the top off (the jeep, not her - that's later), and take her for ice cream and then a little shopping. Stay on back roads and out of traffic (especially if door-less. This still freaks out my wife). She'll love the sun, fresh air, and all the attention she gets from riding in a classic.
She didn't much care for the old jeep when I first got it. I got some comfy seats, installed real seatbelts, and tuned it up (got rid of the old jeep exhaust stink). She is my only co-pilot now, on or off road!