Light probe of under-construction house

My brother is building a house, so I took my mirror ball and the rest of my photo equipment, and took some bracketed shots for an HDR light probe (spherical).

It’s sitting on the ground in the second floor, you can see the framing because the drywall isn’t up yet. Here it is:
http://www.mediafire.com/?mv526w19nci593k

Here’s a background image to use with it:

Please download it and give it a shot if you’d like, I’m not very good with the compositor so I don’t have any good results to share yet (I would be astounded if someone could manage to create a convincing test render using the lightmap on the background photo).

Please share your thoughts/critiques.

Preview:


Here’s another example using Mike Farnsworth’s “Sample as lamp” option, which I believe (correct me if I’m wrong) is the only way to use the full dynamic range of an environment map:

http://img811.imageshack.us/img811/4581/houseprobe2.jpg

Again, full res .exr and background image are in previous post…please try it out and post some c&c.