Yes you would need that style wastegate. Unless you bore a hole on the turbine housing & add an internal wastegate.
Example of where the hole is bored for a T3 housing: http://www.compturbo.com/products/housings

I like this set-up for a internal wastegate http://www.atpturbo.com/root/releases/images/release102705/atp-wgt-023_3.jpg
it allows for a 3" downpipe & a "V" band flange.

You could use that external wastegate, but need to figure out what size valve you need to use. High boost vs low boost will use different size valves to work more efficiently.

External wastegates work better for all out HP & usually better boost control, but require more fabrication & more exhaust pipes.

Internal, easier to use, good for packaging in tighter areas, used more in low boost applications & factory turbo cars for the most part.

My Syclone uses a stock internal wastegate & I run 25 psi of boost pressure.
Example of Mitsubishi Syclone turbine housing w/wastegate:



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