how to buy power cords that fit my components (i.e tight and snug)

Tightening the pins of the IEC is also an option. But electrical tape or teflon tape will do the job just fine, or try some foam tape on the sides that are loose.

Or change the socket on the component.

@millercarbon is right on this and supporting the cable is preferable to tape and other adhesives. 

Greetings 

I have started using interlocking poker chips to support the cable connector at the component end. They work quite well. Stack them as required. Color doesn’t matter haha.

All my power cable are heavy and unruly, but that’s what you get with upgraded cables.

 I wanted to use the really nice adjustable SS or aluminum cable supports but they cost 50$ to 100$ each. They come in different heights. I have 10 power cords in my system. 
Joe Nies
 

I use glass tape to make them fit tighter, and support the cables by straping them to shelves or columns of the rack with small cable ties.