I definitely want to make an active dual exhaust with both ends equally spouting air.

But right now I am un-employed.

I will probably just go with the behind the rear tire method, since it's already there, I would just have to maybe get an elbow or L piece.

Either straight back or to the side.

I am definitely going to bring the slightly rusted pipes up and out of view and only leave the exhaust tip showing.

I will post pics when I'm done - which might be a while...

 

Don't to straight out the back if you go off road at all, any ditch or high angle hill could crush the tips.
Behind the wheels is much safer, look at Streblo's garage, I think he has a snow bank pic where his out the rear exhaust tips are almost hitting the ground. Plus (you as the driver) get the benifit of hearing the exhaust if its out the sides when you go by high curbs, drive throughs, under passes etc etc

 

If it's lifted, going out the back shouldn't matter, but if you're paranoid then running a turndown behind the bumper would be safest, that's what i'll be doing on mine, but only because I like a clean look of no pipe on a lowered truck.