You are finding that going from synthetic to leather...wear shows.
My saddles have all had marks from where my leather stirrup leathers laid against my leather saddle flaps...
No one sees this when you're astride and I would be more concerned if a used saddle didn't have markings from use...
Called shoe polish applied to cover distress marks and then what else have they worked to cover..
Make sure the seat size is correct for your height & weight.
Many adults ride in a 17" or larger seat so length of femur is properly seated on the saddle flap.
It isn't that we can't fit in smaller sized seats but... you need to fit and be in the sweet spot of the saddle where your balance and support are matched with the horses balance point and proper fit.
I am not
a fan of interchangeable gullets...
Changing the tree head does not
change a gullet width, only the very front of the saddle moves and good saddle fit is
more than how it looks at the wither.
Don't be fooled by that "change the gullet" = fits all...cause it doesn't.
Neither of your horses have a ridiculous bone frame and a saddle fit for them would fit most any horse you would be riding.
In the event you purchase another horse, you might need to purchase a specific saddle to fit that bone frame and build...why many people have multiple saddles honestly.
If you're just riding someone else horse occasionally, use their saddle and deal with a slightly different feel.
You should keep your tack for your horses, use tack on a occasional ride belonging to that animal and if a lesson horse use the lesson horse tack again to safeguard your investment.
It also keeps your tack clean and free of germs, or bacteria another animal has and you may not want invading your horse..
So, in Ocala is a place called Good Apple Tack Consignment might be somewhere to keep in mind too...the inventory/stock change often. https://goodappleequine.com/
I put in HDR and Bates specific and was surprised at how large the selection and prices varied new, and used depending upon what link you use.
Just some places you might not realize have used, new and trial programs that might work for you and within your budget.
Let your fingers do some research and look at every saddle shop within 40 miles of home = a lot of places who may have used saddles to try and you might stumble on. Western or English stores can have consignment of any discipline waiting for a new owner to come in and try.
As for which brand...each saddle has pros and cons and when you do used much will also be how it was cared for and ridden in by the current owner in how you feel riding it now...beware.
Not everyone sits a saddle as you do or takes care of equipment same as you...again, buyer beware.
Good luck in your search...