Leave the designing of Phaser effects pedals to the Japanese. With the Ibanez PT-999 Phase Tone, that was built in collaboration with the men of Maxon, they created a classic.
The big brother of the Pearl PH-03 Phaser was described by it's competitor Zvex as "The best phaser ever" in 1980. With the same technology in the PH-03, you cannot go wrong.
Vintage pedal from the 70s, made by Aria.