for the spoiler best bet is either ebay or any Subaru breakers, some people will replace the full boot lid so it has the stronger arms to support it. I changed mine about 4 years ago on the blobeye granted it wasn't a genuine sti spoiler but looks just as good and unless you know what to look for I doubt many people would even know but it wa the same colour as mine. And I just bolted it to the boot lid I had and fitted fine and had no problems.
With the CD players I guess it depends on what you want to spend on it. but anything will be better than the standard setup :)
And you can speak to the guy on here about mapping but to use someone in the UK I would say Jolly Green Monster myself everytime :)
Hope that helps some what I'm off to start a bbq now be back later ;)