My prior tank was 96x33x28.5. From that I went to a 120x30x36. This was the most beautiful looking aquarium. But it was absolutely impossible to work on without have a maintenance person with gorilla length arms.
I loved the look but hated the tank. After a crash wife said order what you want and so we got a 120x48x30.
WIth what you mentioned, it's going to be a custom tank. Custom at the size you're talking about is not any more expensive than a stock sized tank. It's just getting a tank built to suit your situation. If you want a 96x36x25 then order one up. Get the overflow just the way you want. Get the hole sizes cut and placed where you want. Get what you want.
As for flow. 8' of flow is pretty easy to handle. 10' of flow is an amazingly and exponentially harder issue to handle. And - I have (2) Abyzz Flow Canons and a Panta Rhei ECM63.
A flow cannon for an 8' tank is way overkill. For me it's important that the equipment of the tank is as minimally in view as possible. Having 3 bigger oversized pumps to keep out of view rather than a dozen inadequate pumps, that in the end cost the same amount and are not near as effective.
With an 8' tank in the dimensions you are pondering there are reasonably priced pumps that will handle the water movement you want/need. I will tell you that all water movement values printed are not the same. A small Panta Rhei ECM42 will move more water than a physically larger Jebao with a higher listed output - and for less energy consumption.
Dave B