Meshify is one of the best airflow cases on market, if not the best. Dark Base Pro 900 is one of the worst, but that doesn't mean it's terrible.
Aorus Master is E-ATX (30.5cm tall, 27cm wide), Asus Strix is smaller ATX (30.5cm tall, 24.5cm wide).
Almost every case fits both. E-ATX is just slightly wider format, it's not big by any means.