I am looking for a list of promising firms to call and interview to
establish an ongoing relationship for outfitting of our retail units.
We run a hybrid business which can be described as either retail or
promotion which is why we are interested in parties from either
background.

The characteristics and requirements we are looking for are; 

-experience in high quality construction  
-interesting client list (preferably of dynamic small/medium companies
or large companies that behave dynamically!)
-demonstrable experience of involvement in creative projects
-based either in UK and also able to operate in Europe or in Canada
(or other favorable currency exchange exchange country within a 14day
shipping distance)
-experience of car promotions a plus 
-the units will be from 15Sqm - 50Sqm 
-'can do/problem solving' attitude a must.

There's a list of them here...

Choose the relevant type of supplier from the pull down box.

I'd recommend M.I.C.E.

http://www.beca.org.uk/membership_directory.htm