The Shark is longer than the Thunder and heavier as well. Both companies have good reputations. I own a Canik Stingray (CZ Compact clone) and love the gun, but it's all steel, too heavy to be a carry weapon. If you are limiting yourself to the two guns then Bersa is going to be "more compact" and most likely easier to carry.
Another vote for the Canik. With the exception of the D/A trigger pull (very stiff) these are well made guns.
The Shark C is lighter than the Thunder Pro: 27.0 vs 30.7 oz.