is for the Linksys BEFW11S4 wireless router.
Likewise, I like the Linksys WUSB11U SB adapter.
You can get a Linksys PCMCIA adapter for your laptop - I use one and it works like a dream.
You should have no problems with your DECT phones, but there's no such thing as a guarantee.
There are no real pitfalls in setting the network up, provided you make sure that all machines have been configured for networking.
You'll need to site the router near to the BT line, because you must connect your ADSL modem to it.