Be careful they seem to use the psu end connectors to lock you in...so corsair wont fit fractal design etc. Extensions are easier but messier.
Different manufacturers use different pin outs so you can't buy any set as it won't work or could damage something. Seasonic only build 3 psu's for Corsair now and they are a different platform so won't work anyway. I think your best bet is to contact Seasonic and see if they can sort you out with a set of cables.