Need speaker recommendation for modded asl wave 20

I've decided to get my ASL Wave 20 mono blocks fully modded by Response Audio. As of now I've been using a pair of vintage KLH Model Six and would like to upgrade to a more current monitor that will pair well with the modded ASL Wave 20. I'm looking at spending under $1000 used. Any suggestions? I've heard the Epos 12 and liked them but looking for some other alternatives. I also have Dodd audio entry tube Pre amp. My source will soon be a fully modded Red Wine Audio Squeezebox 3.

Thanks