Asher,
Thanks for your kind comments.
I didn't take any photos of the scene with the unmodified 5D, but thought you might be interested in the file before it was converted to b&w -
This was sized for the web without adjustments or sharpening.
Life Pixel did the modification about nine months ago. I think there are several solid companies that will convert cameras to IR, or more correctly, near infrared. The original AA filter is replaced by one that is transparent to near-IR wavelengths. Once a camera is converted, it can no longer take photographs in "normal" wavelength light. It can be returned to the company for conversion back to a normal AA filter, if desired.
I have never used a filter in front of the lenses on my 5D IR. A c.p. might be interesting to experiment with.
Not sure about your focusing question, but all of my IR photos are done with the camera rigged for manual everything - including focus. If the image is sharp at the viewfinder, it is sharp at the sensor. The camera's meter tends to be a little less trustworthy than normal, but a check of the histogram after an initial shot can help you dial things in quickly.
I don't much care for the classic infrared look. It has a gee-whiz factor that gets old quickly. Any green plant material will show up white, so I try to avoid it. The IR files converted to b&w have a different character than those converted from normal color files. Sometimes one is much better than the other, but I don't yet have enough experience to know beforehand which will be which.
One thing to be aware of is some lenses will introduce a light circle in the center of an IR image. I think it might have something to do with the lens coating on the element facing the sensor (ocular element?). The list of such lenses is known, and is published on the web. If I recall, it might have something to do with IR light bouncing from the sensor to the lens, and back again. For example, the Canon 50mm f/1.4 has the problem, while the el-cheapo 50mm f/1.8 does not. On the other hand, the Canon 135mm f/2 works perfectly, so the price of the lens is no guide.
Tom