On OS 8.6+, apart from the ineffective RAM "doubling", RAM Doubler has some minor RAM allocation improvements, but I'd remove it still. RAM Doubler is great for low RAM machines running OS 7.x/8.1 but its usefulness diminishes on more modern machines.

I reckon OS 9.1 is the sweet spot for a TAM, and having VM on does reduce RAM requirements (although I do tend to turn VM off for Macs with 256MB+ RAM). Also increase your iTunes memory allocation, try SoundJam too.