Which PS1 Emulator is Suitable for Game Devopment?

[puggsoy]

I think he means for testing the games (i.e. ISOs) he produces. If that is the case then I can say the ePSXe is probably a good emu, I mean it runs most games pretty much like an actual PS1 which is about as good as it'll get.
But if you're looking to make a game with an emulator then Davy's right, that's not how it works.

I found a Net Yaroze SDK and an official PS1 SDK lying around on the internet, would those help?

An official development kit for what you want to develop would normally helps, yeah