First Magnum Motor, Needs Guidence (5.9L Ram)

ok guys well i got another heard member! here is our new 1997 dodge Ram 1500 with a 5.9L!

anyways its going to be a hauling beast, all tq and good mpg is the plan!

for short term im looking into a full volant CAI, SCT tuner, and Exhaust.

the latter is where im stuck!

here are the ideas

stock mani's thru 2.5" pipe, y pipe, high flow cat, then single three inch all the way out.

same but with shorty summit headers

then im thinking dual 2.5" with x pipe and dual cats. problem is it has the long tank on the drivers side so i dont know how easy it would be.

last if i go thru the motor i'll do a super tq 408 with hughes EFI top end (will do intake when i have the money), dual 3" with x pipe

So what do you think?

P.S.

Add any upgrades you recommend for the ram! and im already changing out those leaky stock covers with push in plugs!