If the offset is correct, yes. Solo II rules allow for +- 1/4" on the offset, which is about 6mm. I believe the Miata 14" wheels are a 45mm offset, so as long as your replacement offset is between 40 and 50 mm, it should be fine.

But remember, it's a Miata. Lightweight wheels are a must! If the wheels you're buying are heavier than the stock 14" wheels, you aren't doing yourself any favors.