I used to do what some of you guys did- tie my split reins together.
Then a friend of mine introduced me to 8' leather roping reins (all one piece). It was love at first ride! But true 8' roping reins are kind of hard to find. Most of them seem to be shorter, and sometimes even the ones labeled 8' are shorter than 8'! I like to get true 8' reins when I can find them, the kind with the water loop ties on the ends, and then make bigger water loops and actually end up with reins over
8'. As a matter of fact, I think 8' is the bare minimum for trail riding (at least for me).
One time I bought a pair of 8' split reins, made myself some extra water loops, and then made them into two sets of 8' roping reins.
I put snaps on each end.
One bit of safety advice- if you are NOT using split reins, and you get off your horse, unsnap one end. My friend had her horse step through her reins and the horse panicked and the leather lacing that ties the water loops on, which you think would break, didn't. The poor horse backed in circles panicked for a couple of minutes before he calmed down enough to catch him. But other than that, we have never had a problem with them getting caught on anything.
I think both types of reins have their pros and cons, so which ever ones you use are sort of personal preference. Personally, I am no co-ordinated enough not drop a split rein, so I like mine all one piece.