I'm busy looking at this too so I'd be grateful to hear how you get on. My dilemna is that all my windows are only approximately 1 metre wide but all rooms have at least two windows. 16 in total, for a flat!
cheapest I've found the silent gliss units for is £235 inc VAT & delivery from http://www.discountelectriccurtains....utoglide-5090/
But nearly £4k for curtain automation is a definate excess. I'm tempted just to put a pattress next to the windows and install some conduit up the walls ready for later installation if I find more affordable units. I was kind of hoping for about £70-80. For the kitchen I'm thinking blinds rather than curtains but can't find any up to now.
How are you going to power them? dedicated 24v radial or mains transformers?