I think you're definitely on the right track with your plans for a ppl during your work leave. You can only really make a judgement on weather this is in fact what you want do or not. If you don't, then you still have an income to return to.
With regards to your choice of schools etc, I'd recomment getting the ground school out of the way first as this seems to be a major hurdle in terms of time scale . Should you choose to do a distance learning course (my personnal choice of actions) then you can indeed carry on with a day job and work in the evening and weekends. This should take about 1 year to complete and it will bugger your social life but at least you can put bread on the table.
Once this is complete then start to worry about the flying. I'd recommed doing your CPL/IR at the same school allowing you to build a rappor with an instructor.
Obviously the first thing to do is get your medical!!!!