I wanna buy flash diffuser. what type is good and suitable? where do i get it?

as for filter, where do i get it and i just want the filter that prevent scratches. is there any such filter?

You might want to contact Jason regarding flash diffusers. He gives quite good prices for really good diffusers. ;)

His name on this forum is 'jasahchun', and you can find his web at JLPhoto

thanks isaac!