Touchin' Down,
My advice would be to do the MCC bit first and then the IR. Unless you have time flying a twin engine, the MCC gives you a bit of a heads up on the procedures, instrument scan etc of flying a non-military aircraft before you hit the IR and the £s start accumulating - you are already paying for the MCC so why not use it as a pre-cursor to the IR by getting in some 'free' twin handling time. My advice would be to go for the biggest jet simulator you can to get handling experience on 'the big' jets (assuming that at Leuchars you are on F3s). There is a course at Cranebank on the 757 I think run by 2 ex-RAF BA pilots - not the cheapest course, but a good starter if you want to see how BA do it and make a few contacts at the same time. As previously stated I would recommend Exeter - they know how to get you through the IR and their photo wall is a testmanent to the numbers of RAF pilots who have successfully 'graduated'.
SG