Should I replace my mags?

[DanSparky]

Help. Any info would be appreciated. Chevrolet Spark 2011. MT. 155/70R14 (no idea what this means, but i think this is the size of my tires).

The chrome plating of my stock rims have started to peel/chip off and the iron/steel rims are showing.

1. Are these rims still usable? Is this just an aesthetic issue?

2. Since replacement mags/tires don't usually carry this size, what's the next best size? I don't like those tires that stick out of the car looking like an ATV with oversized wheels. I just want the next (widely) available mag size.

Thanks!