If you have a bent shock then the shocks you are looking at will sort that no problem, cannot comment on the quality of them as i always buy ford parts or performance parts. The shocks dont come with top mounts so you will need to buy them seperately, once you remove the strut from your car you will have to compress the spring undo the top mount nut and swap the spring, bump stop and dust cover onto your new shock along with your new top mount. The spring will have to be comressed again to get them on the new shock so you are going to need a spring compressor.
Personally i though that the ST170 shocks were different from the other focus, not in form as all focus shocks apart from estate and RS are interchangable, the ST170 ones are just uprated so the shocks you have purchased may produce poorer handling