A point that you have to bear in mind when changing from Integrated to Modular is that the exams only have 3 years to run and you have to obtain both the CPL and the IR within that time frame. You will need a minimum of 200 hours before you can get the CPL and can't even start the course until you have at least 150 hours.
In most cases if you have started an Integrated course the best option is to stick with it until you qualify for an Integrated CPL (150 hours) and then add a modular IR.