Using Auto Paint on Bathtub or Powder Coating

Hello, I'm getting ready to restore an old clawfoot bathtub. I can't find an acceptable solution to the inside of the tub, being, nothing that will hold up for a long period of time. I'm thinking of using auto paint but thought I'd turn to those of you with experience. Another option would be powder coating. Any reason to not use either of these options? If so, please say why. Suggestions? Idyllically, we'd like to get the whole thing stripped and have new porcelain put on, but it doesn't seem like anyone around here does that. I'm looking for the next closest thing. Kits from the store are out of the question, as is hiring someone to come in and do it. Both options do not hold up. Any help you guys could give me would be appreciated. Thank you.

Powder coating is stronger than paint. Your problem with powder coating is finding a facility with an oven large enough to facilitate the tub since it needs cured in an oven.

"Powder coating is stronger than paint. Your problem with powder coating is finding a facility with an oven large enough to facilitate the tub since it needs cured in an oven"

That's what I thought too. I'm thinking of building an oven for it since it doesn't require super high heat and I'm sure there are other things we can use it for later down the road. I'll also be checking around for those in my area with large enough ovens to handle it and see what the prices would be. Thanks for the quick reply.