Seriously considering Denali, performance options?

Hey, I'm seriously considering buying a 2003 Denali. I'd like to do a few things to it and I wanted to know what parts would be good for it and if I would need to do anything special in order to keep it reliable. Here is what I want:
Air filter
new exhaust - headers to exhaust tips - everything. My issue with this is I want something that sounds good accelerating, but I don't want it to be a very noisy ride inside. What parts should I consider getting for this and how much hp do you think this will add?
computer chip - which one is easy to use and will give me good results?
Maybe nitrous (75-100 shot tops) or a supercharger down the line

If I were to get these mods, would I need to do anything to the engine/ drivetrain to make it so it doesnt break every week? Would these mods affect its reliability? If they do what should I get to help fix this problem?

Thanks a lot for any comments!

I'd also consider some suspension mods if they didnt make it have a worse ride or make it worse in the snow.

A few suggestions:

Intake - Volant and K&N are both awesome. The Volant has a sealed box and is a bit more quiet.

Exhaust - If you plan to tow or otherwise spend a lot of time at WOT, headers may make sense. They will not do much for preventing noise. I'm running stock to the muffler, which is now a Magnaflow #12568, with twin pipes exiting behind the rear wheels. To my ears it matches your needs exactly.

Chip. I'm running a Wester's PCM and am ECSTATIC. It is, by far, the most awesome performance mod I've made. If you go that route, make it your last mod (i.e. post exhaust & intake) - he programs to everything else you have.

Suspension - I can't speak to the poor weather handling, but I don't believe there's a mod out there that keeps ride quality identical to stock. I'm running the McGaughy's 2/3 'delux' drop and am very happy with it. It is more firm than stock, though. You may want to consider an anti-sway bar upgrade - either Hotchkis or Eibach. This will prevent some body roll.

Personally I'm not sure I'd ever consider nitrous, but a supercharger is still a fantasy. :) Lots of money that you'll never see again - in fact I'm guessing it'd hurt resale more than help it - but if you plan to keep the truck for a while....

Good luck!

Take care,
Jerry

Hey, thanks for the reply. Around how much HP do you think that a new cat-back system, cats, headers, intake, and Westers PCM chip will give me? Thanks a lot!

I'd guess (and a conservative one, at that) about 30 hp at the wheels...

That number sounds about right. I've got a moderately aggressive tune on my PCM, and I've gained roughly that amount.

You'd have to consult an exhaust pro on the other elements of the system, though. I don't know anyone who's replaced cats on a Vortec system. At some point with exhaust mods you'll run past an ideal situation, where you're adding upper RPM horsepower while stealing torque. Again, unless you spend all day above 4k on the tach, you don't want to come too close to that point.

Another reason to get some solid advice if you're considering that type of money on exhaust mods. What solid information I have gathered is that headers, dual mufflers, and I'd assume hi-flow cats, actually generate a lean-running condition for the engine. So, unless you're modifying fuel flow as well, you could be running into problems.

Anyway, definitely don't take my word for it. The main thing that backed me off from headers was the cost. $500 for a set of JBA's and another $500 to install them. I'm happy with my muffler and chrome tips. :)

Take care,
Jerry

C'mon, Jerry--what's another grand after all the money you put into getting mods and upgrading mods...;)