I have a pair of JBL 1400 Arrays.
I have tried a few different amps on them and have found that the Marantz MA9-S2 mono blocks as sounding superior. I have them matching SC7-S2 pre and SA7-S1 sacdp as well. I have not wanted to replace them. As far as I am concerned, it would be ideal for you.
Resolution/detail/soundstage are (to me) fantastic.