You seriously must be freaking kidding me. You want to be a Powerlifter and you are telling me that Hook Grip is too painful for you to perform. What do you think an 800 lb deadlift feels like to your soul anyway, a Swedish Massage?
Hook grip is TOO painful? This is like saying
"I want to be a pro football player but don't tape my ankles...it is TOO PAINFUL".
Are the helmets messing up your hair too?
Do the team colors not match your eyes?
Son of a freaking monkey's uncle this is right up there with the group of people that will say "I'd do anything to..." and then immediately become Meatloaf and start telling you all of the things that they won't do. Freaking baby powder on a stick, a couple years ago I started having a series of injuries during high dose chemo and I got to the point where I had to make a choice, either freaking hook grip or stop deadlifting and sit on the couch. So I sat on the couch for a couple days and decided that that sucked much worse than some pain in my thumbs. I wanted to freaking deadlift!
Yeah, it hurts. If for a moment you have any clue what you are feeling when you pull a max effort deadlift then it isn't freaking max effort. I can't hear music, I can't hear people, I can't feel a doggone thing except my soul being stolen by The Deadlift Reaper much less a little discomfort in my thumbs. I don't feel my deadlift suit ripping my thighs or the blood dripping down my face, but you can feel a twinge in your thumbs.
If you really wanted it bad enough, you would find a way.