Fiesta ST mk7.5 springs on a mk7 style+?

[dante]

Hi guys, first post here. So I just brought a 2009 fiesta style+ and judging by the previous MOT it needs new 2 new rear springs due to corrosion. Now I've come across Fiesta ST springs from a mk7.5 2015 model that were very reasonably priced and have a few questions since I'm a total newbie at these kinda things:

Are the springs compatible with my current suspension? Will they fit without too much hassle?

What will they do to the ride height of my car? The ST line are obviously lowered from factory, but from what I understand they're stiffer and designed to handle the larger weight of the engine in the ST, whereas mine has a lighter 1.25 petrol engine, so could it possibly ride higher at the front than the back?

Thanks in advance for your help!