Unless you want brand new shiny stuff, the ebay route will yeild the same results for half the price. Probabpy a lil more to have wrx header welded, but still cheaper.
^lolololCompletely understandable, that subie roar is the cause of many a wet dream.
My suggestion would be a uel header swap, and then change up your axleback. Or just weld a different muffler on the existing one
BAM rumble.