If you hear it clicking and it’s not lighting, I would clean around the igniter with sandpaper as they get covered in carbon and grease. If it is not clicking all the time, it’s a faulty igniter on the valve side. That would require service to replace it.

If your going black stainless, make sure you get all from the same brand, so they match as everyone has a different finish. The best brand for Black Stainless is Bosch, they have a true finish. Even if scratched, it won’t show that much. I think you go stainless steel as you’re on a budget and will have so many more choices. Many stainless units now come fingerprint-free, so it’s really the best option. I would avoid Samsung as a brand service, and reliability has been poor.

It depends on the model and brand. You need to take a photo of the serial tag on the inside. Then call that particular manufacturer who can offer a replacement part. Many handles can be self-installed.