Best Speaker wire with Rogue Audio amp and preamp for $2K or less?

I would suggest Analysis Plus Silver Oval 2 speaker cables for that application.  Happy Listening!

What sound characteristics are you looking for?

"What sound characteristics are you looking for?"

That is a really good question.  It is THE question.  I want a warm midrange.  I don't want a bright treble.  The Rogue Audio equipment is revealing but not overly warm, especially for tubes.  I have read that Analysis Plus may be too bright in the treble for my tastes, although the copper may be better than the silver in that regard.  

Consider Nordost.  Even their lower price series are a very good match with the Rogue equipment.  

A suggestion to try the cable lending library via The Cable Co to try out some different cables in your system. I have an ancient pair of Nordost Flatline speaker cables from the mid 90's. They sound really transparent and fast in my system, but they might let more brightness through than might be ideal for your preferences. Especially with digital sources, I've had to carefully choose my source components to reduce harshness. I didn't have that issue with my turntable though.