Maybe I'm missing something blatantly obvious, but I'm left handed and have never had any issues with a RH multi. I used to wonder if I was holding the rod the wrong way or if RH anglers had problems with supposedly RH reels.
I hold the rod on my left side and wind the reel with my right hand and with a fixed spool reel that means I have to switch the handle over to the right side of the body. With a multi, as I hold the rod with the reel facing up (skyward) the handle is on my prefered side anyway.
So, if like me, you prefer the rod on your left side you shouldn't have any problems.
I'm left handed and have used rhw multipliers for over 30 years, you'll soon get used to them just stick with it. Trying to track down a lhw multiplier in certain models is like looking for rocking horse doodah, so you are only creating a problem for yourself in the long-term if you get a lhw model now. If you fish with the reel where it should be, up the butt, and cast with your left hand controlling the reel, there is actually a little known advantage in the leftie using certain rhw multipliers. With high speed models like the SLOSH, that have a 'dropped gearbox' design to accomodate the large main gear, it is much easier to get a proper grip on the reel if you control it with your left, especially if, like me, you've got small hands. My mate, who is right handed, knocks a sore up on his hand every session using the SLOSH because the 'gearbox' rubs on his hand near the first knuckle when casting.
To add to the confusion the convention for fixed spools is the other way around, with lhw reels being far more popular and readily available. For that reason I've always used lhw 'eggbeaters' for both coarse and sea. I am definitely not ambidextrous as I can't even hold a pen properly with my right hand but can still wind in faster than most.
I was told that the convention was that you used your strongest hand/arm to hold the rod and weaker one to crank the handle. But if you are significantly stronger in one arm or the other you are probably doing too much w*****g!? Joke!
I have rarely seen coarse fishermen holding a rod in their left hand but it seems to be the norm with sea fishermen. I've coarse fished for 20+ years and always hold my rod (no jokes pls!) in my right hand and reel with my left. The rod is guided by your top hand when casting and I'm right handed, the left hand just cranks the reel.
I got an ABU6500 SPORTS MAG for Christmas and it's right handed and it has totally thrown me. It feels very strange having to cast and change the rod over to be in my left hand.
My Okuma boat real is L/H but not the best of makes.