well, i've not had a pj for a while and not sure what the best to recommend is.
however if we allow 2k for a good pj, screen and necessary cables (HDMI + 12v switch to make screen go down when pj turned on) that should be enough.
so 3k left, now what are the requirements?
do you want serious power? do you mind how big the speakers are?
if you want a great set of speakers that look nice, sound great and are relatively cheap, go for the svs package but add another 2 bookshelfs to make a 7.1 setup. alough bi-polars may be better for the extra channels.
that lot will set you back around £1100
dvd player wise, can't go far wrong with a marantz DV-7600 at around £550.
after that you will have enough (£1400) for a decent amp and some cabling, an amp that has hdmi switching is going to be needed.
the Pioneer VSX-AX4ASi is coming out soon, 7x140w, hdmi ect. £1000
which leaves plenty for cables, decent speaker cable can be had from fleabay. i got some from germany and it is better than the gale stuff sold in richer sounds. was under £35 for 100m delivered!
will also need sub cables, extra hdmi for the amp to dvd, opical cable and banana plugs if making up your own speaker cables. i highly recommend terminating the cables as it is a right PITA without them