Phase 2 injectors can be de-capped and have been proven to flow enough fuel for 260kw. They flow roughly 550cc when de-capped. Similar to what non de-capped pinks flow.
While you said you're not interested in a top-feed conversion, I have a alternative option which is a Rev D intake manifold, fuel lines, rails, pink injectors, and loom. It utilises the factory V5/6 throttle body and loom, so there's no re-wiring required. Simple bolt-on upgrade and then you'll have loads of injector head room.