Upgrade 2 conductor power cables

I have upgraded the power cables for multiple devices in my Home Theater.  All of these devices used a 3 conductor male plug and an IEC320-C13 female plug.  I am now turning my attention to the remaining pieces of the HT, but they all use 2 conductor wire and either an IEC320-C17p or a C7p or is it C8 (polarized) plug. I'm not exactly sure what they call it but one side is square and the other is circular.  I believe the square side is the polarized connector.  I can find very little DIY information regarding building shielded versions of these type of cords and even less information on where you can buy these connectors. I found one site (VH Audio) that had some info on building a shielded cord for 2 conductor that looks promising but no one sells a C17 plug.  I see indications to use a C13 plug but don't connect anything to the ground connector.  I guess that would work but I think I would just be laying a land mine to walk on sometime in the future.  There are some expensive C7 connectors but I would hope I can find something in the $20 - $30 range.  Am I chasing a Unicorn or is it just better to buy these cords from a manufacturer.  Any and all feed back is welcomed...... let the education begin.

Regards,

BVK_HOUTX