GnarlyZ28

Hi yall
Sorry if i sound stupid, but i dont know much when it comes to headers. First, I was wondering if Jet-hot makes their own brand of actual Longtubes for the LT1. If they do, where can i find them? If they don't, what brand would you recommend for a daily driver? I was also wondering what the loud buzzing sound is that comes on for about 2 second when i turn the car from accessory to off when the engine is cold. Also, since MN does no longer have emissions equipment i would delete the egr and air and probably tune out the rear o2 sensors. Would doing this hurt the car in any way such as mpg, driveability, or engine life?
Thanks