Just bought an Advent 7009 from Dixons - £1380 and damn good spec!
1) Minimum P-4 1.7 GHz (Preferably faster) - Its a P4- 2.2
2) 15" screen, preferably SXGA or UXGA - 15.1"
3) 512k RAM, may be able to live with 256k - Some weird size like 350Mb
4) All-in-one, as in no external floppy / CD etc - No internal floppy (only drawback)
5) DVD / CD-RW - Yes
6) 32 MB or 64 MB video card - Yes
7) 10/100 Ethernet - Yes
8) 56k modem - Yes
9) PC card slot - Yes
10) S-video out - Yes
11) Infra red - Yes
12) Audio out (or at least headphone) - Yes
13) Min. 20 GB (30 GB preferred) HD - 40Gb
14) Preferably Win 2000 preinstalled but not essential - Windows XP Home Edition
15) All other 'bog standard' features such as USB etc - 4xUSB, also Firewire connection!
16) Preferably 'looks nice'. - Yep
17) as light as it can be, but max 3.5 kg - Couldnt tell you but not heavy.