Signal Cable speaker: Ultra vs. Silver Resolution?

HI,

I am currently running Frank's Ultra Bi-wire speaker cable, Silver Resolution IC's, his Magic Power cord for my preamp, Silver Resolution PC on my amp, and the Digital PC for my source. So far, they sound great!

I was considering upgrading to the Silver Resolution speaker cable. Has anyone A/B'd the Ultra vs. the Silver Resolution speaker cable?

Any other speaker wire suggestions? My budget is max $400. It seems silly to spend more on cables, but then I haven't heard any $2000 cables in my system. Not that I can afford to! System consists of Dehavilland Ultraverve 2 (probably going to a SS preamp to reduce hum), McCormack DNA-125 Revision Gold, Sony 9000es with VSE level 6 mods, and Tyler Acoustics Signature System speakers.