The HK offer is just for the .40 USP compact, and is open to any airline pilot, not just FFDOs (company ID required). The offer is mail-in only and the price goes up every year.
The Glock discount is on any Glock handgun, and is open to any commercial pilot (pilot certificate required). The offer can be redeemed at any participating gun dealer.
There is a S&W pilot deal, but I have no details.
Also check out Bud's Guns in Lexington (The LEO website, not the public website) They have good "Law Enforcement" deals for anyone with a commercial pilot certificate. Note that the prices are already discounted and include free shipping to your hometown FFL.
Discount Guns for Law Enforcement by Buds Gun Shop (budsgunshop.com)
That should get you started anyway.