Accepting credit card payment on our website

We are an HVAC company and a long-standing ESC client.  We use ESC accounting.  We want to accept customer payments on our website and just starting to investigate the options.  Our website designer has suggested using a link on the website to an outside processing company, but it would not be integrated in any way with ESC.  We have used Merchant Warehouse/Cayan integrated thru ESC for years, and recently switched to Clearent.  Anyone out there had any experience with this subject?  Would like to hear suggestions, pros & cons.