Looking for an SEO Agency

As part of a rapidly growing organization I am looking for an SEO agency or experienced professionals who can carry out end to end SEO services. The individual or group needs to be able to review our existing site and tell us what works and what doesn't without the usual jargons. Then, tell us what we could do better. Probably help us come up with a better SEO strategy (something well documented) and help us execute it to achieve a SMART target.

My areas of concern right now are my bounce rates, non-returning users and lead generation. Traffic is already good.

Any leads on this would be highly appreciated. Thank you!