Thanks for your advice
I feel a bit stupid asking these questions (as I've been working in IT for years and I am very good at fixing and building desktop PCs) but laptops have different physical design so are new to me.
I can't find much stuff on google to tell me the anatomy of a laptop motherboard or how to repair or upgrade the CPU of a laptop etc.
Some people have said laptop CPUs are welded to the motherboard (which i find hard to believe). if they are not welded then i could get a lower powered cheaper laptop and later on put a faster cpu in it.
Any way these are the models I am interested in
:-
Dell D610 Laptop - Centrino 1.73Ghz / 1G Ram / 40Gb Hdd
COMPAQ EVO N115 LAPTOP - AMD 1.2GHZ/128MB/20GB
HP Compaq NC6220 Laptop - 1.73Ghz / 1Gb Ram / 60Gb Hdd
HP Compaq nc4200 1.73Ghz/ 60 GB HDD / 1 GB RAM
Acer Aspire 1302XC laptop - AMD Athlon 1.6 GHz XP-M
Toshiba Tecra S1 1.4 ghz Intel Centrino Mobile 1.4GHZ/ HDD - 40GB/RAM - 512MB
HP Evo nc4010 Pentium M 1.7 Laptop
HP Omnibook XE4100 1.2ghz celeron M
HP Evo nc4010 Pentium M 1.5Ghz
HP Evo nc6000 Pentium M 1.7
IBM Thinkpad Notebook, Centrino 1.5GHz, 1GB RAM, 80G HD