Stallion brand is cheap imported junk from Asia/China.
I have not heard of the other two, but if they're in the same price range as Stallion saddles, that it's safe to assume that they are junk too.
If you want an affordable, dependable saddle, then you need to go used. Find a quality name brand saddle that's older. Even if it needs repairs, you're still better off. Most of my saddles were built from 1950 to 1980, with one of my husband's saddles from 1920 or so. The newer saddles just aren't built as well as the old ones.
If Western, you're not going to find any 19" saddles that are quality. The tree that would be needed for a 19" western saddle would be too long for almost any horse on the face of the planet. You would end up soring the horse because the saddle length. If the rider truly needs a saddle that big, I would consider going with a 20" Australian saddle. You can find them in that size, though you will need to save up to buy a decent one. Australian saddles (with the padded underside, not the flat ones) are shorter in length and will fit a horse's back better in the larger sizes.
You can buy 17" Abetta saddles in the $300 range new. I have a 17" Abetta endurance trail saddle and it's held up remarkably well. It also is made on a good quality tree that fits almost any horse I put it on (their "regular" tree). Chicks Saddlery has some of the best prices on Abettas (though they charge extra for shipping), and buyabetta.com has the best selection.
If you're needing English saddles, let me know what "style" you're looking for and tree size, and I'll hunt some up for you.
Triple Creek makes an awesome saddle. Might be hard to find a used one in your price range. They are usually running in that $1000 mark used. Triple C, Double T etc. best to stay away. Watch CL I just saw a really nice 15yr old Circle Y Trail and Park for $325.
We had a triple C roping saddle in the tack shop and it was suprisingly nice. I know they aren't high end saddles but this one was built well, heavy and solid with good leather.
I always suggest bighorn but if you are looking for something bigger than a 16" seat...they are rare. I've been looking for a 17" bighorn for the past month and have found 2. Both are out of my price range.