The biggest effect on the tone coming from your exhaust is the model of muffler being used. Having headers/bigger pipes/dual pipes will make a slight effect, but having a raunchy muffler will make all the difference.
My first muffler was a Flowmaster 40 2-chamber, and it was pretty mean. At the time I didn't have headers or cat-back, just a spliced muffler and I got compliments on it all the time from people who heard it, even other modified Dakota owners. The only downside was it droned inside the cabin quite a bit. The new MBRP muffler I have is VERY quiet inside the truck in comparison, with a nice tone when I romp on it.
Cutouts are nice and loud but are illegal for regular use. Combining a cutout pipe with a powerplate such as the McCord unit is fun and can be really obnoxious when open, but only makes a difference when open.
Single 3"/Single 3.5"/Double 2.5"/Double 3" is up to you... Even a single 3" exhaust is capable of handling what most configurations will throw at it.