Dan,
£600 per month towards an ab-initio fATPL ?
Do you have any starting capital ? Or any licenses already ?
Simple maths suggest 60,000 / 600 = 100 months.
Obviously you can spend as you go, but you're not going to be getting in many hours a month if we assume 100/hour for aircraft + instructor to keep the maths simple.
But maybe I've just misunderstood the wording of your question and you're actually asking something else altogether.