External SRAM

Hi

We are a group of students working on porting NiosII CPU accessing an external SRAM along with MAC inside the FPGA. Can anyone help me in connecting my Nios II CPU with an external SRAM... Is it good to use DDR SDRAM instead of SRAM...My device is CycloneIII Eval Board(EP3C25F324C8)..How is it possible to connect an external SRAM to Nios II core...Should i use any bridge in SOPC builder...

Thank U so much...