Need longer run power cable for rel subwoofer

Hi,

I am acquiring pair of REL S5 SHO subwoofers and want to connect both power cables to my power conditioner.

To reach the power conditioner outlet for one of the subs farthest away need a long power cable 10-12 feet....can anyone recommend such a cable....the subs are class D but am I right to assume that alower gauge is better perhaps 10gauge?

I could connect power cable that will come with the sub to outlet instead but have found that even my amp sounds better thru the synergistic research power conditioner