What is the best tool for managing workflow of a web agency (5 employees, 20 projects/y)? A SAAS that makes crm > quotation > ticketing > todo (kanban) > invoice.

I've yet to find a product that effectively handles both the CRM/Sales portion and the workflow portion of a delivering a SERVICE (lots of them will handle logistics of physical delivery) effectively.  for a 5 person team, I'd suggest that you keep the sales info in excel or evernote, or whatever accounting package you are using for now and concentrate on optimizing your workflow, that's where your efforts and value lay at this point.  Once you lose the vulcan Mind-Meld (around 10 people), then you can look at CRM and invoicing again, but likely you won't need it until you hit 100+ clients a year. Good luck.

When I was working in a company with a similar profile as you described, we used Target Process. You can try it for free for maximum 5 accounts.

You can try http://kpi.com for your business. It supports exact workflow you've described. CRM-> Lead Options Adding a Sales Quote: Opening a case (ticket) PM and Task Management: Invoicing:

Hi, I work in Kwamecorp - a digital creative agency with 45 people in 3 offices around the world working on several projects. We've been using Slack for internal communication and recently developed a team tracking solution for ourselves - Nikabot. It's a Slack bot that tracks people's times they spent working on different projects and then creates reports based on the data it received. We've launched Nikabot in private beta so far and are looking for teams willing to try it out. If you are one of them - please sing up at http://www.nikabot.com and we'll send you the free version later.

You should see Brightpod - http://Brightpod.com