Head over to bitcoin and or cryptocurrency related events, and go network there. You're definitely going to get better people there rather than randomly looking for people to work with online. Looking for the right people is going to take a lot of time and effort.
Best advice possible, If you're interested in the success of your project you need trustful individuals built on physical relationship. Depending on online forums like bitcointalk or social media platforms, will only get you those interested in the profit side of the business instead of those who'll buy into the ideas of the project. You need individuals who'll stand by the project even in hard times, who're willing to scarifies their time into building the project from scratch not those you just hired because that's exactly what you'll be doing by looking through the service board or any other services displaying platforms.
Even though you do hire professional from online sources, try to make physical contact/relationship with them it help in trust building. And makes it easier to access the individuals communication/relationship skills which help to bring about a productive relationship in the work environment aka teamwork.