The costel is stock size, and since it comes assembled you don't really know how it was done (always cautious when it comes from china). With the mamba parts the turbo can be rebuilt by a trusted machinist.
You decided to go with pure turbo, a trusted brand which will give you the needed...
If you are a machinist you may have the skills to rebuild it yourself, you can upgrade your turbo with some of the kits available.
https://www.shop.mambatek.com/searchquick-submit.sc?keywords=b58