Our company which sounds similar to the makeup of you company has been using Teamwork.com for project management along with getharvest.com for time tracking and

Our company which sounds similar to the makeup of you company has been using Teamwork.com for project management along with getharvest.com for time tracking and invoicing for a few years now. Both of the tools are great at what they do. We also use Hipchat for instant communication, project specific group chats etc. although lately the service hasn't been stellar. I think we are going to give Slack a shot instead.