DIY extension cord- Help


I want to experiment with high quality 10 guage cable (possibly 8 as well)for extension cords. Can you suggest a shielded flexible cable (not for outdoor use) of a quality suitable for the highest rejection of EMI and RFI?
ptss
Thanks Ozzy. I'm looking at making 2 very short extension cords with maximum EMI and RFI rejection. It's for some ideas regarding parallel ac conditioning. I use and am happy with MIT Cable Oracle power cables. I'm hoping someone here knows of ultra quality 8,9 or 10 gauge cable suitable for high sensitivity application; perhaps robotics, science,NASA,etc.
DH Labs has some excellent bulk cable for a very reasonable price. About 1/3 the cost of Furutech and about the same level of performance.

Regards