New Tire Qs for 2wd Avalanche

[Greg]

My 2wd 1500 Avalanche has 45K on the original tires and they will need replacing soon.  I spend most of my time on the freeway at 75, but also drive about 10 miles a day on gravel roads at up to 50.  The vehicle has always needed a lot of steering correction in crosswinds, and I want to try to help that situation in new tire (and maybe wheel) selection.  I don't want to hear a lot of complaints from my wife about a punishing ride.  I'd like to fill up the wheel wells a bit more, but don't want to lift the truck.  I want to keep the Av for another 5 years (200K total miles) and may start occasionally towing a 5000 lb trailer.

 

I want to move to a LT tire, but not probably not an off-road tire.  A 285/75-16 will look nice, but probably won't help my handling.  Will moving to a larger wheel and smaller aspect ratio help with the crosswind handling?  A retired trucker suggested moving to an Alcoa 19.5" wheel and running 225/70 truck tires and being done with tire replacement for the life of the vehicle.  I don't know if that's an available option on a 6 lug hub, if there's an adaptor available, or if it's even a good idea.  Your suggestions?