Craig,
Hour Builder is right - you really need to review your approach to this in order to do it in the most time and cost effective route.
As noted, you need to do your ATPL theory before you can do the IR. You do not need to do the IMC as part of the ATPL, but it can help make the IR easier - if you are flying regularly and keep current at it.
I also wouldn't do your MEP until after the your theories - again, keeping current whilst you do the theory - plan on at least 9 months if Distance, less if full-time - will cost you an absolute fortune.
There's loads of resources in the Professional training forum - it's probably worht you spending some time in there and seeing how other people are going about gaining their license.
Good luck with it all though!
DW