new exhaust, jetting? filter?

[throttlehappy]

I am totally stock and almost brand new. I am going to buy DMC alien exhaust and i hear way to many ideas on what to do. I would love to leave my lid on to keep it clean, but i dont want to loose that much power. I need to get a set up for two different areas. First, sea level, 50-80 degrees, 155 lbs, dunes. Second at home, 4000-6000, 50-80 degrees. Any help would be great.