Hi Jake,
i set the WB to auto, however I was shooting in RAW so played with the WB in post. I got a 700nm conversion. Since posting these pics I have had a play with processing the photos in Rawtherapee which seems to give me somehow much better results. I tried channel swapping also using gimp. When changing the red channel (r=0 b=100) it looked fine, but when I tried to swap the blue channel (r=100 b=0) the image looked very blue. Dont know why. I use Linux Mint 15 with GIMP.
Yes, you can always WB from RAW, but I've found that aiming at something alive and green, and grass in particular, and using like a grey card to set the white balance helps me start in a good place and get a more consistent look to my shots.
I'm absolutely unfamiliar with GIMP other than to say that I tried it twice, if only to be able to speak to it, and it frustrated me to the point of uninstalling it. I'm not saying it's not a decent or even good program, just that it was so different from what I have that it wasn't worth investing the time in learning it when I had alternatives already installed.
On thing I've found is that when I'm shooting IR in direct sunlight I need to set my exposure compensation to -0.7 to -1.3 or I get blown out leaves and grass, particularly when there's a mix of sun and shadows. It looks like you're getting the same in some of your shots. Otherwise it meters fairly well.
Keep it up!!