Bi-WIRE CABLE - NEED ADVICE

What amplifiers do you have? If they are the same have you considered vertical bi-amping so that you can use shorter speaker cable runs (better sound and less expensive--or better quality). I also agree with Sqjudge, different cables for top and bottom make sense for these speakers. Typically, I would spend 2/3 of the budget for the panels. I also frequently recommend that checking out some cables from the cable companies library makes a lot of sense. They carry most brands and can help you find the right item in your budget and then you can compare a few different cables and see what works best for you. Obviously, it takes a little more time and effort to do things this way--but in the long run it's worth it.

Your statement about vertical and horizontal bi-amping is correct. Like many things in this hobby there are no absolutes. If you are using different amps (or even the same amp of a different vintage/version) then you really have to bi-amp horizontally. If the amps are matched I prefer bi-amping vertically simply because it allows the shortest possible speaker cable. In theory you may get better separation in vertical bi-amping, but in high end amps with very good power supplies I think that would be pretty difficult to hear--but I do think there are distinct advantages of going from an 8 foot speaker cable to a 3 or 4 foot speaker cable.