Alfred McAlpine - not sure
Ardmore Construction - not sure
Arup - very good consultants, seem to be leading the field with their structural projects.
Atkins - again, a big consultant, bigger than Arup, they do everything as far as i can see.
Balfour Beatty - big contractor, i know some people that worked for them and they seemed pretty good. Do alot of roads and rail
Black and Veatch - not sure
Carillion - big contractor
Costain - big contractor
Edmund Nuttall - a consultant?
Faber Maunsell (Scotland) - consultants, smaller than Atkins etc, seem to be more on the structures side.
Farrans -not heard of
Ferguson McIlveen - not heard of
First Engineering - not heard of
Galliford Try - not heard of
Gifford -...... not sure
Graham - not heard of
Halcrow Group Ltd- consultants
Hyder Consulting - consultants, big in water?
Interserve Project Services Ltd - not heard of
John Doyle Group - not heard of
KBR - not heard of
Lagan Construction - not heard of
Laing O'Rourke - big contractor, seem similar carrillion
Mott McDonald - consultant
Network Rail - bashing out rails! - contractor
Peter Brett Associates = consultants, smaller
RPS Group - consultants again i think
Skanska - big contractor, seem very keen to take on civils atm
Sir Robert McAlpine - big contractor
Taylor & Boyd - not heard of
Taylor Woodrow - big contractor
Tony Gee & Partnerr - consultants
WSP Group - consultants
At this stage i think all you can do is have a think about whether you like the sound of consultant or contractors. Also a bigger company would usually have the bigger, more famous projects. So Arup, Atkins are some of the bigger consultants. Costain, Mcalpine, Balfour Beatty are all large contractors.
If you go for a contractor you may well have to move to near the site (they will pay accomodation etc), but a consultant you would have to find one with an office near you.