JDMpreza, We don't have the AEM intakes for the 2.5RS's. The CAI's that we have are the 21-471 model. For the '02-'03 RS you need the 21-472 which we don't currently stock.
WRX 2002, I am not sure if the K&N panel filter will fit the STi or not. K&N doesn't have the STi listed in their application guide yet. If you want to give it a try I will give you refund if it doesn't work.
Kasio, The shipping isn't included but these are quite light so the shipping is pretty inexpensive. K&N Lists the proper PN for your car as a 33-2154. These filters are the 33-2232. Before the 2232 filter was released I used a 2154 in my WRX and it fit pretty well so you may be able to use the 2232 in your RS but I would recommend getting the appropriate 2154 filter.
Here is a link to K&N's application guide: http://www.knfilterchargers.com/search/appsearch.aspx