I have some advice that may be a different direction from everyone else. This would be before you spend a lot of money at once.
1. Get one 240 mm carbon gyuto less than $150.
2. Buy a 1000 or 2000 grit water stone, and optionally a general all purpose stone holder.
3. Buy a better cutting board. Seriously!
4. Stop rock chopping and walking your blade. SERIOUSLY!
5. Watch all of the sharpening videos from the Japanese Knife Imports Youtube channel.
Then spend a couple of months with your one knife and one sharpening stone and it will give you a lot of insight into your future purchases. Do everything with this knife, no matter how big or small the task. Patience is truly a virtue in your situation. You just gotta ask yourself a few questions in the process. Is my gyuto too long or too short. Do I really want to spend the time it takes to take care of a carbon blade. What are my limitations with my sharpening stone. Is my knife too short or too tall for the task. How much does a lack of edge retention irritate you. What am I missing that would be really helpful.
It may seem like an unnecessary expense at first, especially when you have the money to jump in right away, but it will be well worth it in time. You will wind up with more questions and avoid more headaches in the long run. Maybe even save a little money in the long run. Or not, this would is a wallet drain after all. You won't even have to thank me later, even though I know you will want to.