While working as a youth art tutor I was asked if it was possible for me to take a group of staff members for a team building exercise. This was an instant success! It involved a group of 10 staff members and together we produced a large artwork, which hangs in pride of place for all to see. 
Instead of investing in an expensive artwork for the foyer of your company, why not get your staff members involved in creating a masterpiece. This helps foster pride and 'ownership' in the company environment. 
The subject matter of the artwork can be personalised for your company.