First, what is the difference between a 3/4 and a 1-ton? Same motor, same axles--really it's just the rear springs have a little more capacity. As long as we aren't talking dually. For a single rear wheel, each tire has 3,065# capacity so it doesn't matter between an F250 and F350.
It's all bull5hit anyway. Buy the truck you need. My E350 van has a Dana 60. That's not a one-ton axle, except that it is. It's a full-float Dana 60 with the same size bearings as the 14-bolt in my Chevy truck. But newer E350 vans have a semi-float Dana 60 which is rubbish. The E150 uses the same axle.
Worse--GM and Dodge always assigned their vans with 3/4-ton status when they had 1/2-ton parts on them. You see a D20 or G20 or C20 van and it had 5-lugs and an 8 and something inch rear axle.
Point is--what parts does the truck have on it and what do you need. If you don't need a dually, either the F250 or F350 is about the same because the rear tires are the same and the axles are the same and the engines are the same. The 250 might ride a bit smoother because it might have a little softer springs.