me personally, I am not a fan of how silver rims look on a car with darker paint. it does pop, but I think not in a good way. the rim should somehow go with the colour of the car itself. I am a big fan of those Mazda aftermarket rims you posted. I like how they blend in with the paint while popping due to the chrome accents at the same time - looks great.
I would not take a risk with some cheap chinese rims off tirerack. honestly, you're best off getting a set of reputable rims off the local classified ads and inspecting them to make sure there are no cracks in the rim, etc. even if you do find replica rims, you can easily tell if they are road-worthy or not just by looking at the inside of the rim. even the 19" rims have a 55 series sidewall for the CX-5 which is plenty of cushion to protect even the worst replica rims from the worst roads, so I think you will be safe.
now that I think about it, you know what would look awesome on a machine-gray Mazda while also popping out? some nice bronze/gold JDM rims. those would go very nicely with your paint. my BMW is silver, and personally I like how silver rims look on a silver car. my summer rims are these chrome multi-spoke sporty rims, and they suit the silver paint nicely while also matching the chrome accents around the car. I think it's all about getting the right balance between rims that blend in but also pop at the same time.