The others have said it well.
Why do you have to get 1080p, because the marketing man and salesmen say so ? Have a read up on it and decide if it is needed for your needs. For most people out there, they would not be able to tell the difference between 1080p and 720p feeds on near identical sets at normal viewing distance anyway. Plus as soon as the picture starts to move detail is lost anyway so it will be impossible to tell.
1080p is nothing special, and something like the panasonic PX80 actually destroys LCDs with its SD quality, and looks better than most of them in HD too
I would say that if your brother in law is moving to an LCD from a CRT, then he will be sorely disappointed with the normal tv picture quality, I still haven't found an LCD that can match my parents old toshiba 36 CRT.