I don't have a specific company to recommend based on personal experience. However, I think I've seen some mentions of an agency called Increasio that provides frontend development services. You could check out their website at https://increas.io/services to find details on their frontend capabilities and offerings. Looking directly at their services page should give you a clear picture of the frontend development work they can handle and whether they may be a good potential fit for your project needs. It's probably worth visiting that link to evaluate if their frontend skills align with what you require.