Hello,
I bought an actuator from a site which was very good quality. The standard actuator in 12V and 24V are available on this site. It may likely fit to your need as well.
http://www.linearactuatorzone.com/en/linear-actuator-12v-dc-screwdriver-acme-stroke-50mm-ratio-5-lz-00146/p/
There are several combinations, and positioning feedback option available to choose as per your need.
Hope it helps.