"They need funding to carry on doing what they do."
Tickets to the gala and auction evening have already sold out with about 400 people expected to attend, including Mike King.
Miller said he wanted to "blow the target out of the water".
"I think we'll get there."
Proceeds from the dinner and the auction will be split evenly between King's Gumboot Friday and I am Hope.
Miller is currently appealing to businesses for auction lot donations.
He's already locked in a few varied items such as fishing charter tours and an $8000 pergola.
The event will feature a three-course set menu with five drinks per person.
The gala evening will be held on October 29.
More information can be found online at valleydvine.co.nz/mental-health-event