48468 Help Desk, Time Recording, etc

Computer services business needs an application to manage our whole business. Our business activities are implementing packaged ERP & CRM software, network installation, web design, ecommerce web sites, support. Key features: help desk system with customer Web interface time recording and billing support knowledgebase customer systems inventory project management staff scheduling CRM Strong preference for installation of a tried and tested solution instead of new code. Even better if it include use any of the systems we either run internally or install for out customers: Compiere ERP Sugar CRM osCommerce WebCalendar Bugzilla Some features for using PDAs and/or Laptops when offline would be nice to have but not essential. Preferences Ready to use solution, tried and tested Open Source Web interface Linux server Oracle or MySQL database free software, no commercial licences (we are willing to accept alternatives to get the best solution)