Looking for a new email list of potential prospects

My client is in the software industry with a tool that looks after the Intelligent Building Market,

We are looking to create a new sales initiative and are looking for someone to create a new email list for his of potential contacts.

Our ideal contact will be in the following categories and may be found on Linked In or associated trade directories or forums and we are looking for the following information:

a) Name
b) Company name
c) website
d) email
e) phone number


They will be :
1: Commercial Building Owners - They will have up to 6 buildings ( we are not looking for the British Land site companies)
2: Facilities Management companies - so those companies that look after the buildings and the tenants owned by people in category 1 above - ( again not looking for the CBRE's - JLL"s of this world but the smaller operators)
3: UK Based only