I’d go 1” Tbars. Compromise between handling and ride. And inexpensive.

Then big front and a rear bar (rear weight of wagon)

*** I’m suggesting this because of the intended use of the OP’s wagon. It seems like he is looking for significant improved street handing. And wants to drive and enjoy the car on long trips like Hot Rod Tour.

I’m not thinking he’s intending to autocross or roadrace this wagon. ???

I’ve run .99” and 1.14”.

I’ve driven LA to Iowa (1800 miles) round trip every summer for 4 years. It was a stiff ride but manageable. Like Mitch said tire side-wall effect ride too. I could tell the difference between running 225/50/15 and 235/60/15.

I would choose .99” over 1.14” And go with rubber:!lower control arm bushings and offset upper control arm bushings. And definitely run rubber rear leaf bushings. The rear cargo area of a wagon is a sound box. Rubber will isolate the drones, moans, and creaks.