Originally Posted by kok328
You will have to purchase a three wire cord whip (available at the big box stores) and make your connections inside the fixture. . .
But the safety of what you achieve will depend on your knowledge, skill & ability level and how much you copy existing designs that have been UL approved.
I guess one way to do this, since you have a forum, is to post pictures of what you build and see if anyone here can find a flaw in the materials or workmanship or design.
By adding a fuse and a thermal cutout you can possibly make it safer than what is commonly available.