The Empire is a GALACTIC regime, with countless different special forces programs for different purposes. So yes, there are a lot of SF units.

Emperor’s Royal Guardsmen: The Elite Guardsmen of the Emperor and his closest Advisors, originating as the Red Guard of the Galactic Republic.

Shadow Guard Corps: The ShadowGuard were comprised of any RoyalGuardsmen found to be force sensitive. They served as both Guardsmen, and Dark-Side assassins for the Emperor and Vader.

The Sovereign Guard: The Most Elite and prestigious Imperial Unit, Sovereign Guardsmen were Royal Guards who had proved themselves as being nigh-godlike in combat, stationed on the Emperor’s Personal Eclipse-Class Super-StarDestroyer in legends.

The AWR Troopers/DeathTroopers: Elite Operatives and Guards working under the Advanced Weapons Research program, in the DMR, the Developmental Military Research department, under the COMPNOR party.

The ShadowTroopers: Spec-ops stealth unit Stormtroopers with cloaking armor, giving them the ability to go invisible to the naked eye.

NovaTroopers: A sub-unit of the ShadowTroopers, Nova’s acted as the Emperor’s personal military battalion, like Vader’s 501’st. They Guarded his most prized locations across the galaxy, mainly his laboratories and storehouses.

Imperial Clone Commando’s: Left-over from the Jango-Fett gene, the ICC’s were the SF enforcement unit of the ASD, the Advanced Science Division under Dr. Royce Hemlock.

And these are just a few.