72' Chevy P30 Step Van wheel question

[Steppie]

Hello all. I just acquired a really decent 72' Chevy step van and I see the tires are 7.50R16LT. I know that is 16 inch wheels, but how wide are they? The reason I ask is I want to put some spiffier chrome wheels instead of the stock wheels. Bigger width will give me better handling right? So what are the min. and max. for this vehicle? Can someone help with this? Also, any good places online where I might find some cool wheels to swap the old ones out? So far I just see wheels for regular vehicles, not these larger commercial trucks. Thanks!