184 is just the DDR SDRAM pin count.

As long as you get DDR SDRAM, not DDR2 SDRAM which is 240 pin, [SDR] SDRAM which is 168 pin, SODIMM DDR2 SDRAM which is 200 pin, SODIMM DDR SDRAM which is 172, or SODIMM [SDR] SDRAM which is 144 pin. Other types are keyed in such as way as they will not fit (SODIMM is very short and quite obviously wrong).

Don't worry about buying PC3200/DDR400 over PC2700/DDR333 is it's available. Due to supply, DDR400 is usually cheaper than DDR333. It is rated as 33MHz (66 MHz DDR) and 500 MB/s faster than what you have, but is capable of running at speeds as low as DDR266/PC2100.