Long Speaker Cables/Short Interconnect or reverse

I'm considering re cabling my system and have a question regarding the desirability of using of long speaker cables with a short interconnect, as opposed to shorter speaker cables with a long interconnect. I currently run a 21 foot pair of speaker cables from my equipment stand to my speakers, and a one meter interconnect between my pre and power amp. I could move my power amp closer to the speakers which would allow me to use a 11 to 12 foot pair of speaker cables, however would necessitate about a 11 foot interconnect. My preamp is an Audible Illusions L3 which does not use a cathode follower and has a relatively high (1.2Kohm) output impedance, however they claim a longer interconnect can be incorporated as long as it is of a low capacitance type. It is a single ended pre so a balanced interconnect is not possible. So is it advantageous to cut the speaker cable length by 10 feet or so if the interconnect is lengthened by 2+ meters? My speakers are specified as 8 ohm nominal, 6 ohm minimum (I read a post by the technically well versed Almarg who stated that allowable cable length is dependent on speaker impedance), and my amp is solid state with an input impedance of 50K ohms. Although logistically trickier, I could also possibly move both the preamp and power amp closer to the speakers, and run the longer interconnect from my cd player (RA Opus 21 with an output impedance of a low 100 ohms) which would need to physically stay where it is
Thanks in advance for all your advice...