http://www.satcure.com/reviews/review91.htm - Satcure used to sell a stacker/destacker, but as their review says, they discontinued it because it didn't work very well.
You are asking the cable to handle double the frequency, and it's losses will be more than double per unit length, so add up enormously unless the run is short.
Another alternative to the flat window cable, might be threading a short length of ultra-thin co-ax through a vent, but finding suitable connectors to make a water-resistant link from standard sat cable to bootlace cable would be difficult.
With higher losses per unit length, it would be impractical to make an entire run in thinner cable.