for the pillar get dual aeroforce gauges and if you wand a "wide band o2 gauge" get a narrow band instead. the gauge will only be for looks but it will function. only reason you need a wide band is for tuning. honestly if i were you i would just get 3 aeroforce gauges so they all match and call it a day unless you plan to heavily mod then i say get the wide band.

as faras a cat, just get headers they come with a downpipe wich deletes the "u"bend and adds a high fow cat.

tint the windows for sure.

mufflers are personal prefernce so that u to you, i say leave it stock and enjoy the superchargher wine. now if you go turbo i say open downpipe is the best sounding. open downpipe on a sc car sounds like poop though IMO.

if he sold is pillar pod just google gauge pllar pod for 00-05 monte carlo and the only one ever made will come up and buyit and then paint it to match your interior (what i did)

hope this helps

 

If I do ened up going the pillar route I was thinking all Aeroforces to match would be nice but not totally necissary. And for dual Aeroforces are we talking dual Interceptors? I would be able to display more info that way. I'd get headers in a heart beat but don't they have fittment issues with our radiator fans? I thought thats where the issue came into play anyway. Correct me if I'm wrong. That also may have just been an issue with Speed Daddys there was a post on it awhile back but I'm failing to remeber the full thing.

 

Here's what my SG2 looks like:

 

My Speed Daddy's have about an 1/8th inch between them and the fans. Never had a problem with them and I've had them since December of last year. Just use a lot of high temp RTV and seal them up good. Took me and a friend maybe a full day to install, which included letting the car cool for about 6 hours lol. We took breaks often and didn't rush it. I bet if you were in a hurry, they could be done in less than 4 hours. I think they're a good buy for the cost. Cheap KR killer