Well people do train with Hickory training tools which is heavier/denser than white oak and of course significantly more than red oak. Purple Heart is also heavier/denser and while I do not train with it I have not heard any complaints either. The heaviest sticks I train with are Kamagong which is a very heavy/hard ebony wood found in the Philippines. It is definitely a very heavy hard wood and perfect for self defense but.... what is necessarily always good for hitting someone may not be the ideal training implement. Kamagong is typically thought of as a great tool for self-defense and also for personal strength building but you will not find FMA practitioner's hitting kamagong sticks together in training because the sticks might shatter sending a piece flying. FMA practitioners also do not like hickory all that much on average, etc. This is a potential common problem the harder the wood is. Where as a lighter training wood like rattan is used in stick on stick work. Rattan slowly shreds but does not splinter very often. That is why they are perfect for incredibly hard striking drills that frankly would fry and or shatter many hardwoods. Yet, I would not want a rattan stick for self-defense instead I would want kamagong for it's heaviness and density and of course they are just a substitute for a blade. Japanese white oak is like a perfect blend of hardness and density plus the ability to absorb repeated blows without damage. Hickory is good as well but a little heavier. Many people train with hickory and enjoy it. I have some hickory three foot and four foot sticks and they have lasted a long time. Though I totally prefer my white oak sticks of the same sizes.
What you want to find is the right wood for the tool you are using with the the density and hardness plus weight that you desire.
Personally I do not think you could go wrong with White Oak or Hickory for what it sounds you like you want.
Top Ten heaviest woods: Top Ten Heaviest Woods | The Wood Database
Top Ten hardest woods: http://www.tenorama.com/en/ranking/top-ten-hardest-woods-world
Here is the janka scale for a lot of different wood: http://tinytimbers.com/pdf/chart_janka.pdf
more janka: The Janka Hardness Test for Hardwoods
What you want to find is the right wood for the tool you are using with the the density and hardness plus weight that you desire.
Personally I do not think you could go wrong with White Oak or Hickory for what it sounds you like you want.
Top Ten heaviest woods: Top Ten Heaviest Woods | The Wood Database
Top Ten hardest woods: http://www.tenorama.com/en/ranking/top-ten-hardest-woods-world
Here is the janka scale for a lot of different wood: http://tinytimbers.com/pdf/chart_janka.pdf
more janka: The Janka Hardness Test for Hardwoods