VDR,
I'd go with short interconnects / long speaker cables, unless I had a real good reason why I wanted long interconnects. Really good reasons include, for instance, component placement constraints.
I could also build a case for long interconnects
if the intention was to use them as tonal filters to mask another system or room deficiency e.g. harshness/brightness. Long interconnects are more efficient filters than short interconnects.
But I'd rather solve the real problem than fight the symptom with a band aid. Consider:
The interconnects between pre- and power amps are the most sensitive connection in the entire system. It is here that signals have the lowest level. Therefore any kind of noise that gets through here is most detrimental, because it too will be amplified.
Conversely, the connections between amps and speakers are high power. A noise level which is huge compared to the interconnect signal level will be insubstantial compared to the signal level on a speaker cable.
The argument that short speaker cables have a lower resistance doesn't hold water. My cables are nothing special, however their DC resistance is only about 1 Ohm per kilometer! (Capacitance is low as well.) In other words the difference between a 1 m cable and a 4 m cable is only 3 mOhm. Yeah, that's substantial. Not!
(Note: those are SI units. I am back in Europe now. Meaning that I no longer measure speed in furlongs per fortnight - or lengths in feet. I still appreciate a pint, though.
)