I have a SBA3 brace I got with a PSA 6.5 Grendel pistol kit. I like the SBA3 brace but the SBA4 brace is very popular. There are some very expensive pistol braces on the market but it boils down to personal choice. I like my SBA3 better than the blade a friend has on his 7.62x39 AR-5 pistol.
Here is the S B Tactical brace I’m using.
another popular brace is the Maxim Defense pistol brace but more expensive.