[Arran]

..and if possible to meet the resistance of 3.2K to keep the DC Volts the same so you don't have to add a resistor in series. But if you do, it is not the end of the world.

 It may or may not make a difference, if the wire is thicker the DC resistance may be less but the inductance may be the same, I somehow doubt that the DC resistances were that consistent from speaker to speaker anyhow. The only way to find out is to test it, if the B+ is too high that's very easily corrected, in terms of hum it won't make any difference at all.
Regards
Arran