Swede, as far as my poor experience goes, the final qualification of a sword is up to you with your whole background, skill, aesthetic, and style. Some very knowledgeable guy may and will gladly help you, but it's your money (or, life?), not his! If there's no quality difference recognized between sword A and sword B in your eye, there IS no difference for you indeed.
Triton said heavy is very bad. It must be true to him. Some swordmasters told me the same. But they also told me, newbies (with practice less than tens ofyears) should have heavier sword for
a) it has more inertia that assists cutting power.
b) it gives more accuaracy. Its centrifugal force stables the sword in right orbit.
c) beafier blade is less likely to break under inadequate cutting angle. As the practitioner's level is lower, cutting angle may be shallower to put lateral force onto the blade.
d) longer blade reaches further. They told me extra speed that can be gained by light sword does not compensate for reach until I'll be WELL trained (like them).
Hope this helps to get better and more precise criteria for you.
P.S. sword swinging should not turn the blade. Even if it looks like home run, there are applied quite different techniques.