Hi Adam,
It's nice to see how passionate you are.
First things first get you class 1 medical. It should be the very first thing you consider, because without it a commercial flying career is a non starter!
I've just turned 21 and I've been researching flight training since the age of 18 once I finished my A-Levels. Within that time I've changed my mind between modular and integrated training dozens of times. I sat an assessment for CAE Oxford. I was quite optimistic that I would stroll out of training into the right hand seat of an A320 and if I'm perfectly honest I probably could have. Easyjet was hiring waves upon waves of fresh cadets from CTC, CAE and FTE. I looked at my finances exactly the same way you are right now. 'If I cut this cost I can save this, If I don't do this I can afford this.' It turned out that parents were willing to help me fund my training. They relied on my proposal to them about the way the market was. It would of been very very tight but it was doable. I made a mature decision to not go ahead with that route. I don't think I would of been able to handle my training knowing that once I walk out the doors the crippling debt will swallow myself and my family home if I didn't secure that job fairly quickly. I started working on the ground for Jet2 the same year and got speaking to a pilot apprentice that was about to start his type rating on the 737NG. He'd paid 40,000 for his training. Don't be too quick to turn your nose up at the modular route. If money is an issue you will get the exact same piece of paper as an integrated student would. Airlines now do not care what your training background is aslong as you have a strong record with good results and first time passes. I mean look at Easyjet, the one airline who notoriously only recruit intergrated cadets opened up places for cadets from any training back ground and look at Ryanair who have just reduced their type rating bond!
I'm mid PPL now, flying 4 times per week all paid for by working, looking at moving straight onto the ATPLs after, with some hours building done in the north of England. A kind FO at Jet2 has a share in a Cessna he's looking to sell. Looking to have my full training done in the next 2 years!
Honestly Adam, you're only 15 mate so research every possible thing you can, build a network do some PPL flying and you'll thank yourself later!!