Toshibas or Sonys if second hand, is spares situation easy ?

Hi
I need to get a second hand laptop under £450 with separate graphics card giving OpenGL, so most Nvidia or ATI should suffice.
I have heard it said that Toshiba are best avoided, go for Dell for repairs and spares, is this so, and what of Sony or other leading brands ?
Obviously a brand new one has warranty, but second hand, who knows when something may break or be in need of replacement, anything from a missing keyboard button to a bigger part, screen light etc. I know nothing of laptops, I only have Tower unit experience.
On the other hand, if Toshibas are well built, then little chance of needing such anyway ! ditto Sony. I shall ensure what I get is 100% ok, as much as is possible with any ebay sale or other purchase.

Cheers
DBenz