I'm with xiphon, cat 6 cable really needed? I've run my own cat 5e cable through the house with basic connectors at each end and it handles gigabit connection speeds fine, the setup managed a real world sustained 70megabyte /second transfer rate between 2 pcs on the network when copying hard drive data from one to the other which is about as good as it gets.
The broadband gets no where near to saturating the network, so to me it wasn't worth the extra expense of cat 6 at any point.
Rather than daisy chaining in a line, it might be better having single runs of cable from the BB router outwards to each of your switch setups ( office, lounge, PC's ), that way each setup has a more direct access to the internet rather than fighting against other devices further up the daisy chain.
But that would also need compared against what other data traffic you may have ... i.e. do your PC's feed a lot of data to the TV (streaming films etc ? ) That would be a higher data amount than broadband, so it would be worth making that link direct.