Speaker cables for Quad 63's

I just picked up a pair of Quad 63’s. I’m currently using Analysis Plus Solo Crystal speaker cables that are bi-wired. All RCA’s are Solo Crystal as well. Since the Quad’s are single post I figured it would be a good time to try out some different speaker cables. Amps are Music Reference RM -10 Mk II’s in mono block. I’ve searched the archives but there is surprisingly little information. Any recommendations for speaker cables would be very much appreciated. Budget is around $ 500.00 - $ 750.00 for something used.