Wrt the Sanders and Walker observations - these are not mutually exclusive.
Put each monoblock near its speaker and cable accordingly. Generally, shorter speaker cables are preferred assuming your preamp has enough output voltage to drive the needed length of IC.
You'll get different opinions here, but just take a look at pictures from CES or most dealer showrooms if you doubt placing amps near speakers. Or ask a few amp manufacturers - you'll be hard pressed to find many (any?) who advocate long speaker cables.
Of course the cables themselves have an impact. Cable geometries influence capacitance and inductance. A cable with, for example, high capacitance will smear a signal more over a long run. Keep overall reactance on the low side without disproportionate weighting of one over the other.