you need DDR2 memory. Nothing else matters. All and any DDR2 memory will work. The numbers you are referring to are the timings, which affect speed. Nothing to do with compatibility. I recommend you get the least expensive from a company either:
OCZ did not make the list due to the seemingly high failure rate.
If you are really worried about compatibility, you can find a list of memory that Asus tested with your motherboard:http://usa.asus.com/product.aspx?P_ID=KC8yHOfBMCe9SlrP