We do not offer professional services ourselves and we don’t want to endorse anyone in particular, but here’s a few resources that UI designers use when they look for jobs, as well as a table of possible contractors from Upwork. You should post your job offering there. Good luck with your search!
Job Announcements on Twitter
Professional Association Job Listings
- CHI-JOBS Email List
- IA Institute Job Board
- IXDA Interaction Design Job Board
- Usability Professionals Association Job Bank