MPC ClientPro 545 help needed

Just picked one of these up and want to increase the RAM and add a dvd/cd burner but getting mixed up about what I can or can't do. It lists on the internet, and I hope I got all the needed info, the following: "MPC ClientPro 545 with DDR SDRAM - ECC 400.0 MHz PC3200 DIMM 184-pin Dual channel memory architecture - Controller Interface Type Serial ATA-150 - IDE" My questions are do I have to put ECC memory in or can I use non-ECC which is cheaper? and on the dvd burner can I use a SATA drive or not and what do I need to do to install? cables etc. I think I need a drink... The older I get the less I seem to know...