I am using streak. Works with gmail merge. Best technique is to see Youtube tutorials fro streak.
I can highly recommend Pipedrive CRM. Very intuitive, easy (with a mobile app and call logs), email integration, super price!
My vote is now firmly in favor of HubSpot CRM. Beautiful, reliable, simple, and FREE until you want to use some of their sales tools. Then it's $50/user/month.
I'm a big fan and respect that it's hard for a big public company like them to enter a new market and execute on it so well. Their CRM is a very nice product.
The simplest idea is to use Google Sheets with an notification/Calendar app added in. I know..a step above excel but still it is the easiest, plus you can custom design to your specific needs.
I have found hubspot to be a wonderful system primarily aimed at the needs of a startup. I use it extensively, helps me keep track of all that you mentioned, just doesn't send mails. You may wanna check them out as well.