After you install CFW you dont really need any seperate PSX EMU. Unlike SNES or GBA emus, there is little install on your part other than POPSLOADER. This will allow you to select the firmware, in most cases 3.71 or 3.72 that works best for your PS1 EBOOT.
COPY AND PASTE THIS INTO YOUR BROWSER.
Code:
http://www.pspmod.com/forums/custom-firmware/31954-popsloader-every-pops-3-90-m33.html
Install instructions are in that post.