I find this is one of the toughest questions to answer, we are not looking at how to sell or how to at impress people - all these can be learnt.

We are looking at when the willing parties just in time to meet each other (i,e, the buyer just in time want to buy the office space that you have and willing to sell).

We are looking for the right time to execute the ripe situation.

The timely quality information is the trigger point.

Given the deficiencies in reaching out the ideal customers in time, there are two common approaches:
1. increase reach out capabilities - to convert more quality leads
2. improve inbound management - to nurture customers and prospects so as to realise sales.

Combine the advancement of technology and modified marketing strategy, the gap of serving wrong prospects can be narrowed. You should try different ways to collect real leads/ database (remember the more the better but make sure real and are prospects based on your customer profile). Look for places where you can capture quality leads regularly at low or reasonable costs.

Build a nurturing and maintaining model by using a simple CRM (many very good CRMs in the market at zero or low costs). This is the place where the right customers can be nurtured (now - s/he may be a buyer or referrer)

As for the right companies, you can follow the above same approach, but your criteria will change accordingly.

Hope the above can help you. :)