CRM which links to Simply Accounting
The best place to start is with Sage's own CRM. The two solutions would work as companions precisely because they were developed by the same company. It'll be familiar and comfortable for you. Also Simply Accounting (now Sage 50) comes with a library of third party add-ons that might suite your needs, but in my own search I didn't find a complete CRM solution.
I hope that helps and good luck with your search.
Perhaps Simply Accounting has a list of compatible solutions! Another alternative is QuickBooks accounting, which is widely used especially in the English-speaking markets. BPM'online CRM connects with QuickBooks and the data is seamlessly transmitted.
Check it here http://www.bpmonline.com/QuickBooksIntegration