If you are non-technical, you ideally need a senior technical partner/cofounder/employee in house first who can then either build a team in house (ideal for long term) or outsource non core components.

The worst combination is a non-technical founder outsourcing to another firm. Even if you are lucky that the firm is good, they will always treat you as another client and you will always be at their mercy. I don't recommend going that route unless that is the only thing you can do for the moment.