buying Mk 6 fiesta for son 1.4 or 1.25 engine?

[ironv8]

only £25 cheaper for the smaller engine even though a few insurance groups different. 74 versus 79bhp so I'm guessing not much noticeable driving experience. Is the little Yamaha designed motor the one to go for ? I'm also reading that the 1.4 needs a timing belt at 10 years/100k. which would be the age of car I'm looking for. You can pick a tidy one up for £1500 on a '55 to '57 plate.
Thanks