It's rather funny reading that IR seems to be all about glowing trees. You've got to be kidding!
When upgrading my 10D to a 5D2 I kept the 10D as there was nothing wrong with it, and sent it to LifePixel to convert to IR. The biggest decision you need to make is what filter to put in it. This is vital as you probably don't want to have to change the filter again! (In my case this involved sending the body overseas on a long trip.) I went for a B&W filter instead of colour. Another important consideration is what lens is calibrated with the filter. For example, Lifepixel will calibrate to a EF 50mm f1.8 by default unless you specify a different lens or send them the lens you want calibrated.
Given the right light and weather, I can now shoot IR handheld
(a major advantage of converting) and in RAW (another important factor). Silver Efex Pro luuurvs the resulting TIFFs and most of my IR work you would not immediately spot as IR, but instead very strong B&W, eg landscapes with good cloudage.
Hot spots are a major issue and it can take some effort getting an effective lens combo. But with the 10D, the EF 24-70m f2.8 is producing pin sharp
IR images before
any sharpening in DPP. I've found other lenses simply won't produce focused shots though.
I know of 2 people who have had their 5D2's converted to IR. Hands down, and despite recently selling the camera, the best IR photography shot with the 5D2 is by Toby Pocock of the UK. Check out his stunning long exposure IR 5D2 work at http://www.redbubble.com/people/tobypocock/portfolio/ir