Hi Frank – it is absolutely possible. You can get the FIT for every (eligible) technology you install.
In terms of CHP boilers the issue is there are not that many to choose from. Flow is a company offering them, but under their business model they take the FIT payments for the first 5 years and only will install them in certain circumstances (i.e. if there FIT return is big enough to cover the cost of boiler + install).