Well, IMHO, spend the extra $30 and get an AEM intake. You can get them for $170ish shipped from
www.groupbuycenter.com
As for the header, stainless should last longer and be more durable in general. You don't just get the looks.
The exhaust is largely up to personal tastes for the sound. If you buy a name brand, ss exhaust, you should be in good shape.
What I'm trying to say here is this: spend the money on quality parts in the first place, and you'll be happier and won't have to replace cheap junk.
Good luck