Your Japanese components match very well with Harbeth and Spendor products. You might want to audition the British BBC Sound. Don't know your budget, but there are some nice reviews out there on these products, including Harbeth's new 40.1s. Not surprisingly, the reviewer is using a similar setup as yours. I think that Shindo/Harbeth has all the tubey magic you could wish for.
PS: Some Audiogoners referred me in 2007 to a wonderful dealer named Gene Rubin Audio in Ventura, CA who specializes in these English products. He might be able to offer up another opinion. I have not bought anything from him, but he has wonderful insight from handling these products over three decades. I can also recommend a Gallo/English dealer named Sound Asylum in Venice, California.
PS: Some Audiogoners referred me in 2007 to a wonderful dealer named Gene Rubin Audio in Ventura, CA who specializes in these English products. He might be able to offer up another opinion. I have not bought anything from him, but he has wonderful insight from handling these products over three decades. I can also recommend a Gallo/English dealer named Sound Asylum in Venice, California.