I would start with Audio Research, Pass, Magico, Conrad Johnson, VAC (as @tomcy6 mentioned). Boulder, Wilson… many of the most respected high end names are American.
I have to throw in Sonus Faber (Italy) and Koetsu (Japan). Dcs and Linn… the UK.
If you are putting together a cost effective high end system… you do not have to pay more… you are going to be buying primarily American, you do not have to pay more.