HI Murray_NN,
From my experience, I would sugguest you go to where you get the best value for money.
I done my writtens at ATA Coventry and could not recommend them enough. I Then did my BCPL/IMC and CPL upgrade at Oxford (1998/99) and would not have done it that way again.
I would have done my BCPL/IMC wherever I got the best deal and went to Oxford for the Upgrade course. The quality of the Upgrade course was much better than the BCPL/IMC at that time.
I have heard good reports regarding Multiflight, so have a good look at them, but dont rule out small/local schools for the BCPL/IMC, as in real terms you are never going to use this licence in its own right, but more of a step on to you fATPL.
To be honest I dont think going to Oxford helps you get a job/interview any quicker than any other school.
What matters is that you have the licence. They may ask at an interview where you did you IR, but the long and short of it is that it is broadly irrevelant.
Whatever you decide, I wish you the best of luck.
Its a fantastic job when you get there!