Various power cables, which would you put where?

That's really weird.  The hiss/buzz shouldn't be happening if they are all plugged into the same outlet.  It sounds like something is wrong with that outlet.  Could be something like the copper connectors between the top plug and bottom plug are broken and/or barely touching.  Or it could be a loose wire connect on the outlet, or the outlet is not gripping the plug correctly.  Maybe have an electrician look at the outlet?

As far as the power strip, that DIY one from Parts Connexion looks pretty good for the money.  Be aware that the outlets used are just common 15 amp outlets ({nothing special), but it will allow you to use good internal wire.  And you'll still have to get a separate power cord to connect this to the wall.  You can go to local hardware store (or home depot) and get a couple feet of 12 awg solid-core wire (or stranded THHN).  Or you could order a couple feet of the following Neotech 12awg Solid-Core UP-OCC COPPER Wire, PVC Jacket:

http://www.partsconnexion.com/wire_hookup_neotech_cu_pvc_sc.html

Look at the installation guide:

https://www.dropbox.com/s/ueiowanv5jqvtp4/triplex.pdf?dl=0

Examine the pictures carefully and make sure the black wire (hot) and white wire (neutral) are connected to the exact positions shown in the picture.  You want to make sure the hot/netrual wires on the outlets are connected correctly (yes, this matters).  If you use the Neotech, just put black tape around one wire so that you can use it for hot wire.

This DIY kit will allow you to upgrade the outlets in the future, if you want to buy something like Furutech FPX Rhodium.

If your budget is really limited and you still want to get something better than the trip-light, then go down to Home Depot and look for something like this:

https://www.amazon.com/Westinghouse-28374-3-Outlet-Outdoor-Extension/dp/B005XKCB1I/ref=sr_1_55?s=lamps-light&ie=UTF8&qid=1491109804&sr=1-55&keywords=3

These are usually heavy duty cables with stranded 12awg wire and the wire is bonded/clamped to the multiple outlets.  A cheap way to get good current into your devices.

The Furutech etp-60 is nice for a prebuilt distribution block and is probably a good value if you can get it cheap (there’s one on ebay for $199), but it uses the gold-plated FPX outlets and you still have to get a power cord to connect it to the wall. Since you are looking at the DIY Parts Connexion kit, maybe something you can do is go down to Home Depot and get an electrical box parts/cover like the following:

https://www.vhaudio.com/hotbox.html

The get your Furutech FPX Rhodium outlets and your choice of power cord / male plug and build it. In the end, you’ll get a better result than the etp-60 for the same amount of money.