Cup Grinding Wheel

I just purchased a 05' Pontiac Sunfire a few months ago, since then there have been non stop problems with the wheel bearings. After those were replaced a grinding noise started up from around the driver’s front wheel. It becomes very obvious at 40 mph and higher. I have been told that the tire is cupping and that there are metallic specks on the brake pads. There does not seem to be any problems with the wheel bearing part as that has been checked and rechecked a couple of times. No one is very sure what the issue is anymore besides just guesswork and a vague answer and I really don’t feel like spending a fortune on more diagnostics that won’t tell me anything. Can anyone help here? I am very tempted to seek out a car compacter and some popcorn.