Did the IR before the CPL, I felt the two are,like said above, different types of flying. Totally up to you which way you want to do it.
One point also is that doing the IR before allows you to have a reduction on the CPL hours down to 25 for a trade off having to do an extra 5 hours for the IR. I found this to be a good way of doing it because chances are the IMC may be new to you so those 5 hours are welcome.
Best of Luck
