Digital Brain is having a half price sale until July 27th. I can recommend Multiplex Vocoder for making vocoder sounds with your own instruments (standalone that can use any vst or au plugin including Kontakt, U-He, and Omnisphere, Reaktor, etc.)
Use this code at the shopping cart: SUMMERNOW
"Our Summer Sale is here, don`t miss this chance to purchase any of our software tools at 50% off for limited time.
Voxpat. Monster, creature & robotic sounds designer. 74.5€ (Regular 149€)
Voxpat Player. Voxpat lite version. 14.5€ (Regular 29€)
Batch Pro. The ultimate batch processing tool. 24.5€ (Regular 49€)
Talkie Box. Walkie Talkie, Radio & Telephone sounds designer. 24.5€ (Regular 49€)
Multiplex Vocoder. Your favourite synthesizers as vocoder carrier signals. 24.5€ (Regular 49€)