If you’re in an area where you can make 400 yard shots, I’d skip the suppressor and spend the $ on the rifle; even something like a Ruger American Predator with a threaded barrel plus a can and fees would run well over your stated budget.
A CZ 527 Varmint (24” hb, dbm and single-set trigger) in either .204 or .223 should be well under 700 bucks. I have a .204 (discontinued) Kevlar stock model and can highly recommend those CZs. You’d have to stick with the excellent 39 grain Sierra Blitzkings, as that’s the heaviest bullet the slow 1:12”-twist barrel will stabilize (a common issue with almost all factory .204s), and the report - to my ears - is a tad louder than a .223. On the other hand, the .22 cal. high-bc 53 V-Max is a dandy round in any .223 I’ve shot, and it comes in loaded Hornady ammo, in case you don’t happen to reload.
Oh, if you’re serious about a .17 Fireball, and live in Central PA: Shaw Barrels and Custom Guns (Bridgeport?) could probably put something together for maybe $200 or so over budget.
Might also reconsider ever taking a shot without hearing protection. Good luck in your search!
