I am having g a hard time finding a saddle pad that I like for my horse. I have tried many and bought several but would 

I would like some kind of therapeutic type or a type of foam insert . The problem is he is very around right now, he also has a bit of a shorter back because his but is a tiny bit higher so nothing longer then a 30.I bought a different saddle for him that fit perfect but he seems to be getting a tish sore in fromt of his kidneys . I do have a square squirt saddle. I was told the csi pads would roll on him because he is so round.not as wide in the withers.I am also trying to stay with in a reasonable budget like around 250.I do love my best ever and just got him a best ever Cadillac but it seems to thick. Any ideas.

I'm in the market, too. I watched a video about Larry Coats saddle pad this morning and think it would be good for my horse. Here is the link if you haven't seen it.  https://coatssaddlery.com/balance-pad/  Have a good day. 

I sold all my 5 stars and saddlerights and went with best ever Kush pads. Absolutely the best IMO. I really don't care for the OG series. They do make a nice one with inserts in their Cadillac series. 

I sold all of my five star pads and I only buy the impact gel pads. I buy their barrel pad because it is 28x30. 30 inches long is too long for my geldings back. I ride in a treeless saddle and I couldn't get rid of a few bumps directly along his spine when I used the 5 star pads. My trainer told me to try an impact gel pad and within a couple weeks all of his bumps along his spine were completely gone and I have not had that problem since. 

the saddle may not be wide enough and not sitting on his back good.  It could be bridging that's making your horse back sore.