Jon,
Is it better to run long speaker cables or long IC's. It sounds like in you situation it must be speaker cables. The problem is finding a quality cable at 35' that doesn't break the bank. First of all at that length you should use atleast a 14 gauge wire due to signal loss over the length of the cable. I use a 35' run of Synergistic Research Alpha Quad in a bi-wire configuration to feed my rear speakers with execelent results. This is not an inexpensive solution the cable company has a 10'terminated pair for $281 and change. I estimate a 35' pair to be to be about a grand terminated. But the nice thing is you can keep your bi-wire configuration with this cable.
Another place to check is bluejeans cable. Canare 4S11 Speaker Cable, Terminated spade to bi-spades or banna to bi-banna is $77.25 per cable for a total of $144.50.
Good luck in your search.