Hi there,
I second @joshinator Zap are probably good for kits.
If you want to made them by yourself, He are some advices :
The most important thing is the cable diameter. You want to be as close possible to the paracord, else this will be bad looking. But you want to be able to put the sleeve on the chord. So you need to have the good cable.
This one is the key to success. As you can see it's 24 AWG (American wire gauge). For some reason I get others cable with the same size but they are too big for the paracord, even 750. This is for 25 meters so this is an investisment for multiples cable…
Paracord size 550 to 750. If the color that you want is disponible in 750 then go for it. Remember that if you coiled, you need a more important section. Paracord 1250 can be good if you have a big sleeved cable (not the one that I recommand). You can get them on paracord planet or paracord.eu or elsewhere.
For USB connectors, choose something
like that As you can see there is no plastic shield and you can cover them with heatshrink.
You can get Lemo connectors on Aliexpress (I don't know if they are genuine but I have some and it's pretty decent).
For USB-C connectors that's a little bit complicated. At this point I have done some research and there is some USB-2 connectors that you can use on Alieexpress.
For the Heatshrink the most important thing is the reduction factor like 2:1, 3:1 or 4:1. If you take 4:1 reductor then you can cover a female usb port and also your chord so it’s probably perfect. The size that I have used is ≥9.53 mm for covering the male usb (if you don't have those with plastic shield as suggest) cable and that will work for mini / micro usb but this can be a little bit big for others use so I suggest you get a size a little bit smaller. Anyway, having different heatshrink size is very confortable, so maybe buy a black or transparent kit that will follow all your needs for a lot of time. I have those in multiples colors, also made by techflex. I suggest you to have a heatshrink at the color that you want but also take some black / translucent one for your next uses.
If you want to have a techflex sleeve on the paracord you can see that there is multiple size. I have used PET Expandable braided sleeve called Flexo. There is multiple size but you can see on this table the minimal size (when folded) and the maximal size when stretched. What you want is 6.35 mm size. It's good with 550 paracord size to 1250 (and probably 3 time bigger).
