Once all my training is done i intend to get an FI rating and working as an FI to build my hrs up
As i understand it, instructors are poorly paid, so after paying your £450 repayment i doubt you'll be left with much change. Think about it. Think hard. Think about paying for your revalidations, medicals, petrol/fare to the airfield, your lunch, your odd beer in the evening, Your famiy's Xmas presents! Its not impossible, but be prudent and think about it.
Oh, and £25k+cost of PPL (£30k total) is fair enough. What about £6k for instructors rating. What about the inevitable type rating be it a Shed or 737? Another £10-23k?? Be prepared to spend some SERIOUS money. I'm not discouraging you, merely warning you. But hey, it isn't stoping me, so if you want it you go for it!