It's a personal thing, but I wouldn't hr build before the ATPLs simply because you wont fly for another 9 months, so when you come to do the CPL you will be awfully rusty.
I would do the ATPLs, fly a "little" bit during them, then when you are done do the hr building then go straight into the CPL.
As for the IR before CPL, again this is a personal choice, and personally I would do the CPL first.