Just in case anyone else is interested in this topic, here is the answer (in a way):
All our C-Series TRCs only include DAS. At the moment there are no plans for TRCs with other adapter/storage options.
If you would like to use C-Series rackmount servers with FC storage, this would make your solution specs-based. The easiest way to get there would be to take one of the C-Series TRCs and add a compatible FC HBA (compatible here means listed in the UCS HCL as well as in VMware's HCL). This way the deviation from the TRC could be minimized.