Those are what I had in mind, just hadn't found time to find a source to suggest for them.

I meant conventional as in typical EFI injectors, not CIS injectors... As opposed to special injectors that don't require a holder, which I've never actually seen. Like I said Kinsler has the EFI...

There are fuel injector mounts that will do what you want, they use conventional injectors clamped in the mount. Look up Kinsler, I believe they have them.