6.0 swap, need exhaust suggestions

In about a week or so, I will be swapping out my 5.3 to a 6.0 LS6. For now I have the stock exhaust that came on my 2003 Avalanche.

Here is my want list:
1) Single or Dual doesn't matter (hopefully not straight out the back)
2) Able to keep my spare tire in stock location
3) I have always used Dynomax Ultra Flow Welded on my "street" cars. Love the sound, low, deep and not too restrictive. So, some thing along the lines of the sound and performance of that.
4) Adaptable from a stock configuration and later headders.
5) Do not want big obscene tips
6) Does not hang low like and eyesore

Magnaflow. You running a cam or anything? I have headers and dual 3 inch mags and a very large cam. I have a nice deep sound. Mine are also dumped in front of the axle making it louder. You could just do a muffler swap and keep the stock exhaust?

Not a big enough cam to worry about. It is not a "race" build, just a little bit more power than stock, that will maintain a daily driver durability. I was thinking of being able to get away with just a cat back, but wasn't sure if it would hurt the performance of the new engine. Thoughts?

Typical headers and a 3" catless y pipe and a 3" catback will work just fine.

How much will it decrease performance if I stay stock for now? I may not have enough time to do all of this while on block leave, I may have to do it when I get back to Stewart. That will be a 15.5 hour drive door to door.

Anyone have experience with Stainless works headers and or catted y-pipes?

I bought a MagnaFlow 3" SS cat back today, got a really good deal on it, could not pass it up. it fits all my perimeters, especially with the cost, or I would have not done it. I'll get the rest maybe in Jan or Feb. I appreciate all the help.