Sky Replacement 3d pan a few questions

Hello,

I have been slowly learning AE for the past few years. I am finally getting good enough to create temp comps.

I want to do a sky replacement on a shot that rotates 360 degrees. I have a good camera solve, color range to key out sky is good.  I have a sky  element that is 12079 x 2416. My project is 1920 x 1080. I dont understand how to bring the sky in larger than the comp size. I tried it as a new compostion, but could not properly link the 3D camera to it.  How to import it so it is larger than the project/comp size? The other question is, I set the ground plane based on good track points. How can i move it over so it is in the enter of the comp? I guess pan behind tool doesn't work in 3d. I am attaching some screen grabs. Thanks for any help the community can offer.