Joomla Mo has some type of cart integration working
http://www.joomlamo.com/joomlamo/index.php
The data in webERP is kept in MySQL tables. Report writers commonly support reading MySQL tables.
Here is one:
http://en.wikipedia.org/wiki/Crystal_Rep...ta_sources
Payroll is a pain in the butt. I used to sell, support, and customize accounting software that included payroll. The government can change the rules without notice and many other features ie union dues, legal payroll deductions, pensions, auto deposit, and so on make it very complex. If you are just starting a business, use Paychex or one of their competitors as the time you save will pay for their service. Monthly payroll takes me 30 seconds with them today. Even with more employees the time savings is enormous. If you grow larger then use online payroll software where all the updates come as part of the deal. Here is one:
http://payroll.intuit.com/ and there are competing vendors as well.