AZ_CZ, congrats on your Sar! I love mine and would actually take it over my EAA Witness P if you told me I had to choose between those two alone. Unless you plan on shooting competition, don't worry about messing with the trigger as it is fine for what the pistol was designed for; it has a very smooth single action and what you would likely expect for a DA pull.
To answer your question about compact polymer frame 9 with a decocker, the only two pistols I can think of that immediately come to mind (because I own and love both) are the P-07 which I stole off of Gunbroker for $380, and the Walther P99 AS. But, the Walther is striker- fired and also, there is no way you will find it anywhere near as affordable as our clones or CZ parent.