In search of a good CRM

I’m overwhelmed with all the CRM options and I could use some suggestions. We are a small IT company with its own datacenter, in addition we offer cloud services and sys support. I am the business administrator and I need a CRM to manage our clients, a safe place I can add all their information documents, track financials and all the work our sys admins do for each client (contracts, purchases, changes). We use excel and I would like to have an actual tool for client management. We have around 100 clients and just three employees. TIA