So if I want them to stick out more do I get a wheel with more backspacing or less backspacing??

I run stock 20" Rims with Nitto Terra Grapplers LT325/60R20 and had to use 1/4" spacers all around - be prepared to use/need spacers if you go with a wide tire.

Both. Offset is the direct cause of the amount of backspacing on a wheel. So, having a 19.05mm offset on a 9" wide wheel results in a 5.75" backspace. Offset is measured from the centerline of the wheel and backspacing is measured from the innerlip to the rotor mating surface.

2002-2008 wheels are 19mm offset w/5.75" BS and 4th Genners are 19.05mm offset so they are .05mm difference. That equates to .02"..aint much at all. Not even noticeable.
This will help you out alot.
https://dodgeforum.com/forum/3rd-gen...dodge-ram.html