I agree with Dodge Man on the rock: I would want the rock even if I had a 4WD truck unless your plans for the property do not include keeping the driveway where it currently is. For tires, I would simply go with what you know handles well and lasts well on your truck.
Of course there is a right way to put in gravel driveway which includes excavating and building a base with the right size base gravel and the adding subsequent topping layers.
However if that dirt and grass griveway is actually holding up pretty well as dirt alone then I might not goto to all that expense. I would top it with small course gravel. Small course gravel interlocks on itself and stays put as you drive over it where round type gravel gets pushed to the side by tires. Additionally,course gravel will still drain water away. FWIW: My driveway was never done right by the list of hillbillies who lived at my property before me. Topping my mess with small course gravel has made my situation quite acceptable for not much money at all less than $40. Gravel is cheap if you have ability to haul it yourself of which I did many years ago. While I have a dump trailer now, I have yet to haul gravel in it. I did my driveway using 5 gallon buckets. Gravel pit has a minimum charge if they load with their loader. You might only have $6 worth of gravel yet it $30 if they use their loader. However they permit loading by hand yourself for free which I did. The buckets method also kept me from terriby overloading my 1/2 ton truck and I could dump the gravel exactly where I wanted it. smoothing could be easily done with my foot if needed so one could get by without a tractor (although I have several). Now I was only doing a couple hundred feet not 1/4 mile of drive but you get the idea. With a 1/4 mile drive it would pay to hire the dump trucks and have em spread it as they dump.
