I’ve fished southpaw on a spinning reel since I was about 5, but started on a right hand bait caster when I was about 10.

Tried using a lefty bait caster, just can’t. Wish I could, at least on a flipping rod.

I would look through eBay regularly, it might take awhile, but one will show up eventually.

Good luck on your search

Which is your dominant hand? If you are a right handed thrower you should be able to use a lefty if you had never started with a right handed reel.
Reason I know this is I know many lefties who use right handed reels and don't know why right handed people use right handed reels.

I would recommend you go out with only a left handed reel a couple times. Once you've done it awhile it gets easier. For me, I was forced to use a left handed reel when I broke a bone in my hand.
By the time my hand healed I could use either one.

I cast a spinning rod with my right and reel with my left. I cast a bait caster with my right and reel with my right.

I wish I could! I’ve tried so hard. I bought a left bait caster and tried for 3 or 4 months, it always felt wrong to me. Wish I knew why.

I am as uncoordinated as anyone with my left hand but after a couple hours it got more comfortable.
For me, I cast with the right so all I had to learn how to do with the left hand was how to reel. Just do it a while and compare how your hand moves compared to how it moves when you reel with the right.
After my hand heeled I realized I could pitch with my left arm with almost the same accuracy but no matter how long I did it the left arm got weak faster than when I used my right arm to pitch or cast.

I had to learn how to set a hook with my right hand which was most of my problem. I didn't realize I was using my whole arm to set the hook with my right arm, keeping it almost locked straight, but once I realized I mostly used my forearm to set the hook with my left and started doing it with the right it became easier.

I have both right and left hand reels on the deck all the time. All my pitching reels are left and so are some of my casting reels. My daughter who fishes with me does the same.