I would start with new speakers, I am not a huge fan of the Coherent Source lines high end although the low end wasn't bad...
What about your system don't you like or are you not satisfied with? I have listened to a lot of amps and can not tell which is "really better' louder, looks better, heavier, yes I can tell all of them, but better sound? not really that easy with the new stuff, My emotiva xpa2 sounds as good as any $10-15K amp I have ever heard, plus the cs is good, the price is good and the warranty is good, and its built like a tank...
But anyway, room treatments and speakers are going to make the biggest difference, is the amp you have now loud enough? and you are not going to get a better turntable for the price, I own the same one and have compared it to a lot of tables, its awesome...
$1300 could buy you a sb1000 subwoofer and a pair of ascend acoustic sierra bookshelfs...