If you honestly think that as a 19 year old you can just walk into a supermarket and collect £40k from opposite the fish counter with no security then I'm afraid you have a fairly delusional view of the finances required
If you can get a loan with BBVA you can probably get a loan with another bank, perhaps not as much but at least something, and probably for a better rate
As for working minimum wage for 12 years then doing it after saving, if you're still on minimum wage after 12 years then have you really got the aptitude to command multi-million dollar jets?...