Shorten those lengthy power cords?

Sure you can. You can use Hubbell 8215C (about $20) or Wattgate 5266i (about $15) power plug. No need to buy anything ultra expensive.

Another excellent choice is the Marinco 5266 or 8215 plug, very easy to install and a very secure method of securing the cable ends inside the plug.

Consider resale (if that day comes) otherwise go for it.

Xt16,
I'm thinking of just doing the ones that are detachable,
therefore replaceable.

If these are just standard computer iec cords, nothing special, it may not matter what plug you put on them. If you plan on doing DIY later down the road and making some better cords, go ahead and buy the expensive plugs - you can always use them again when you make your own cables. Just saying, as long as you are buying the parts, you might want to make some DIY cables.