stack speakers question

Hi, I'm looking at putting the Thiel SCS4 on top of the MCS1 with a very short speaker stand on floor if any. Can someone tell me what kind of speaker cables are needed to achieve this? Using BAT VK-600 amplifier *Pretty excited about this experiment actually*
Since there's a 2dB difference in efficiency and they are both 4-Ohm speakers you might want to bi-amp them with at least one of the amps having a volume control to adjust for their difference in relative loudness.

You can use any speaker cables that fit the connectors to try it out.

With only a single stereo amp doing this will be problematic from the standpoints of different efficiency and the resulting very low impedance load.
thanks for the info plato, I really wouldn't want to harm the amplifier could it do damage? I should also point out that the amp preamp only allows me to go to the first number on the vol control as it is and its loud enough. (some cd's 7) Both are BAT and i'm using balanced runs. Is this an impedence issue, Should I have more range in the volume control?
I wanna do a stack of buttermilk pancakes and Pioneer CS-88's. A triple stack would be cool.
I thought so shakeydeal but just had to ask anyway to see what other people would think. Just reading up on bookshelf stands alone facts are thrown around about cabinet resonance which sort of tells me no (not smart to stack)

As per slik's recommendation pancakes it will have to stay. I guess cabinets like wilson creates that get stacked are built and specially seated atop one another