I have questions about building my own turbo setup

Ok so I have a 2011 xp900 that I want to turbo. I have turbo many vehicles in the past but the rzr is new to me. I would like low boost for now. 8-10 psi. Now I get how to build everything till I get to the fueling. I see some companies send you a manifold with an injector bung built in. So is there a way to just add bigger injectors and tune them. That’s what we always did with cars. I emailed a few companies but no one will sell me just their fuel setups