"Invisible" wasn't mentioned in the original post or any subsequent post. The post asked for Stealth, "real stealth" and the responses were based on that. Perhaps the intent of the question did not take in to account the nuance of how Perception and Stealth mechanics work in this game, so the right question was not asked.
For example, the power "Shinobi" from Blaster Ninja Training grants +35.5 feet StealthRadius PVE (self only) - same goes for "Field Operative" from Blaster Devices which grants +35.5 feet StealthRadius PVE (self only).
The "Celerity: Stealth" IO slotted in the Sprint power grants Blasters +30 feet StealthRadius PVE (self only). Use Shinobi + Sprint slotted with Celerity: Stealth to get +65.5 feet of stealth.
As a comparison, the power "Stealth" from the Concealment Pool grants Blasters +55 feet StealthRadius PVE (self only).
Blasters are not getting any higher stealth from any other powers outside of temporary base empowerment craftables by themselves. Ask someone on the team for "Grant Invisibility" and you'll also get another +55 feet StealthRadius PVE (self only).
Then take in to account the amount of Perception that certain mobs have in-game. Some will see through any amount of stealth.