ImmortalTom or Inksgirls would be a good bet. They're not even that expensive to commission, all things considered. You'd need to go through Patreon, though; I'm honestly not sure where else they're even accepting commissions these days (if anywhere!)
Tom:
https://www.patreon.com/immortaltom
Ink:
https://www.patreon.com/inksGirls (currently closed for commissions, so you'd have to either wait or get lucky in the monthly request giveaway)
There's also Bokuman, who, last I heard, was still taking commissions - but is pretty pricey. Then again the art is amazing, so. Contact:
contact@bokumanstudio.com, examples of his work at
https://www.deviantart.com/bokuman
Herretik is pretty good, and does comic pages. Currently closed for commissions, though, so you'd have to wait.
https://www.deviantart.com/herretik/posts/journals
Last I heard, Splutt was open. Reasonable prices:
https://www.deviantart.com/splutt717...ions-795733832
You *might* be able to get Just Add Water to do one. I do think they prefer to work on their own OCs, but you can ask.
https://www.patreon.com/justaddwater
ChubbyPumpkinn does cute art and has experience with shrinking sequences. They tend to go back and forth on whether they're open for commissions, but are pretty reasonably priced.
https://www.deviantart.com/chubbypumpkinn