I also am planning on buying SotN soon. I haven't played it and I'd like to. Trouble is, I don't have a PSone...
If you've got a pc from at least the last 3-4 years ePSXe is the way to go. the emulation on SOTN is perfect, it slows down entering some menu's if you're playing from a cd but if you have the ISO it runs smoothly - also comes with built in gameshark and you can use save states.
It's not particularly difficult to set up, it supports joypads and there's a website you can get all the plugins you need. The Bios SCPH0001 etc can easily be found on most peer to peer clients and that includes the european and japanese bios so it doesn't limit you to an NTSC copy of the game if you can find a cheaper PAL or Jap version.
You can probably find a pre configured ePSXe if you use torrents. I own the game but my bedroom is small so emulating it via this program is nice and convenient, stops me dragging the PS1 out of the cupboard and creating a mess with wires so there's that benefit too.