I would imagine CPO would cover it, but I wouldn't know.
FCP Groton makes some high quality parts, with lifetime warranties. If you're not mechanically inclined, you probably won't want to do this job by yourself. Depending upon how many miles are on it, you might want to do more than control arms while you're in there (if applicable). At least I would if personally doing the job.
BMW X5 Front Control Arm Kit
FoCo? I can recommend a mechanic if you don't already have one..
cheers,
nick