Hi,
You should be able to flash the unit using the Blueflash tool which comes with the Bluesuite tool from the CSR web site which I discuss in the below link (the Bluesuite tool set not Blueflash).
To use Blueflash you would need to use the SPI interface on the modules which is good because it is far faster than any other method. You do need to buy the CSR SPI chip from Digikey as the SPI interface is proprietary.
For the firmware files themselves you are going to need to get them through one of our more specialist distributors as we do not have any on the source (not good I know). If you contact one and the project can be registered with the relevant apps engineer who supports the distributor you have chosen sending you the files for the firmware you want.
Regards
Matt