High RPM shifts, W58 or R154?

[GST95]

Thank you for all the feedback.

My main question hasnt really been fully addressed yet.

I know the r154 is extremely strong, but it is also bigger and heavyer.

The w58 is decently strong and is smaller and lighter.

If I put this setup in a really small car i might not be able to fit a r154 without cutting out and reshaping the tunnel. If it does go into a light car, there will be less strain on the tranny because it is easier to push less weight. So, 400hp in a 3500lb (I dont know what your cars weight) might be max for the w58, but 400hp in a 2000lb car may last for 50k miles.
For that reason I stated in my original post that I dont want to know what will or wont work. If I go with a mid-heavy weight car I know I will need at least a r154, but I am exploring my options right now. I may decide that a 3rd tranny from another make might work better for me than the r154. Im just looking for consistant max rpm shift points right now.
If X tranny can hold 2000hp, but cant shift above 6k rpm it will be useless for what I am trying to build.
I hope this better explains what im trying to figure out here.

The engine that im using has a stock rev limit of 7500. For this project it will be setup for somewhere between 7500 and 9000 depending on many variables.

Will I be able to consistantly shift either of these trannys at this rpm in stock form and if not is there anybody that makes upgraded syncros or anything to help them?

Thank you