Someone just messaged me about my purple Abetta saddle for their Paso. Not sure if that was you?
It really depends on your horse’s conformation. My friend and I ride Pasos. She uses Australian saddles on her horses. I prefer a dressage saddle. I have also used a wintec western and a Fabtron saddle on different Pasos over the years. It really depends on the particular horse. Some are very round and need a very wide tree, others are more average in conformation. My friend has one with razor withers and a back like a thoroughbred.
As for lightweight - you want either an Abetta or semi-synthetic western saddle. Most fully leather saddles weigh 28 lbs for a western saddle. You want a round skirt to avoid rubs on a short backed horse.
Pasos can get cinch sores easily - a mohair girth works to prevent rubs. Sometimes you may need to add a fleece cover over that and cut it to size.