so if one is replacing the hubs with flanges anyway, is it still wider?
'hub' is kind of a misnomer. 'bearing hub' would probably be more accurate as "hubs" are usually thought of as lockouts (Warn, Milemarker, etc.)
The dually vs. SRW. If you run the 'bud' type wheels on the rear, a factory truck will run them on the front. They need to account for the offset of the wheel to do so. Thus you have DRW and SRW front hubs.
The only real difference is the wheel mounting surface. The DRW is about 4" offset from the SRW. I've seen guys use dually hubs to run the H1 wheels to keep the hub protected.
Dually hub with H1 wheel
SRW hub with H1 wheel
Dodge and Chev bearing hubs interchange. You can get a NEW bearing hub through Six States or on Ebay for roughly $200 per side in common bolt patterns (8 on 6.5, 6 on 5.5, 5 on 5.5, etc.). That might be the way to go depending on your chosen rear axle. The Dodge 'external' hub is kinda the low end of the bearing hub due to the limited availability of lockouts. There's only a stock 'Selectro' type hub or a drive flange. There was not an easy 35 spline upgrade until about a year ago. Now you can get 35 spline drive flanges for the external type Dodge hub (I've seen them on E-bay for about the same price as internal drive flanges).