Are you looking for reins that you'll actually be roping with? If so, then you'll likely need something that is smaller diameter than most of the yacht rope reins out there...unless you have really big hands.
I have huge hands for a girl and the one time I tried to use a yacht mecate set while I was roping, it took up too much space in my hand and made it hard to handle my rope.
I much prefer a good set of leather reins. What I used to do for roping reins is I would take one of the reins from a split set, punch holes in the tail end for the water loop, and turn that into my roping rein. For some reason, it's hard to find a pre-made leather roping rein that is long enough to have slack in your reins and wide enough to have some substance, but a single 8' rein worked well for me.