Professional Choice are great. Have a pink skinned sensitive horse and I have ridden him for miles and miles in very hot weather. Never rubbed or caused concern. Use the cinch for western saddle also.
I use a Jeffries neoprene non elasticated one. Her saddle slips side to side a lot because she's so wide and round. I use it with a very non slip numnah and her saddle stays in place and had no issues with rubbing so far either.
I use the Thorowgood cob girth on my current welsh d and my old Irish cob x had one too. They're non elasticated and have split ends - smart, not expensive and very durable.