I've written about this before but I want to write about it again. If I do come up with the funds to buy and restomod a car I will have the following priorities: safety, reliability, and practicality.
Safety. This involves making sure the electricals, brakes, seatbelts, chassis, air bags, and other related things I can't remember, are in great condition. This means at least making sure the brakes are in great condition with no leaks in the brake lines. Maybe even upgrade the brake lines and refresh the calipers and other components. It could also mean replacing the wiring harness and electrical components with new ones. Costly yes, but crucial to make sure the car will be able to protect the riders.
Reliability. The engine, transmission, and other important components should be problem free. Could include having to overhaul the engine and transmission, specially after all the stuff we've experienced with our 2001 Rav4. Replace all fluids and make sure everything is in tip top condition.
Practicality. At my age my idea of a practical car is a relatively small, spacious, and fuel-efficient car (like my main dream practical car, a Honda Jazz gen 2). Also included in being a practical car is the creature comforts so having a reliable AC and a "modern" head unit, so Android Auto and Apple Car Play ready head unit. I'd also love to add roof rails that can carry a cargo box or bike rack.
And that's it. I do want to add "performance" mods. Stuff that aren't practical but will hopefully scratch my car guy itch. Things like adjustable coilovers so I can raise the ride height by two or three centimeters. A carbon fiber hood to lighten the car and make it more fuel efficient. LED bulbs for most lights, excluding the headlights. Fog lamps, both front and rear, for those really dark and low vis situations.
Out.