Locate supplier of ceiling grid for lighting

[foxhole]

Trying to find something like this
http://www.flickr.com/photos/13897970@N03/3482545299/
for toilet ceilings to cover lighting, needs to be suitable for cutting to size as all of the ceiling spaces vary in size.
Any suggestions, [central London].

 

[Zambezi]

Try CPD in Twickenham (they have branches elsewhere AFAIK) 02088915971