PCSX2 would not be working without a BIOS file so you already have it...
ive got the bios and my settings are all on default.
what would be the settings that i can set that gives good graphics but at the same time playable without a problem
So are you using the SVN now or 0.9.8? You have to experiment on that because it varies from game to game. To get better image quality increase the internal resolution of GSdx. For more detailed explanations read the configuration guide.