flexible tube and compression fittings

[Kaldskryke]

I've got a rather small case that I'm planning on watercooling (again) and so flexibility is a concern. I also like the look of compression fittings a lot more than the plastic barbs I currently have. I'm looking at 3/8" primoflex pro LRT because some independent tests show it to be a strong contender for tight bends. However, this tubing has an 5/8" OD, and almost all of the 3/8"ID compression fittings I've found specify an OD of 1/2". Would it be difficult to get the collar onto the fitting, or would I still be okay?

Since I'm Canadian and there seems to be a lack of WC parts selection up here, it looks like I'm limited to bitspower or TFC fittings. Feel free to prove me wrong.