Here goes.
Its a goos idea, get your MEIR in a seneca or something that is commonly used on ATO's then you have it ready to go.
You then hour bulid for you CPL doing SE IFR (when the WX suits).
Then by the time you have your commercial you will also have close to the 50 hours IF required for you to teach IF once you have an instructors rating.
It means more money over a shorter period of time but will give you a large advantage come that first IF job.
splat
oops I just realised that your an ozzie, not sure if thats how the if instructor thing works over there. In NZ you need 50 hours on an IFR plan before you can teach any IF to students doing a IR.
Sorry if its not applicable, but I have seen a few people do it this way and it seems to work out better in the long run.