Web-Based Law Practice SaaS

I’m building a subscription-based practice-management platform for law firms and need a full web application that lawyers can access from any modern browser. The core modules must include case management, billing & invoicing, and document management, all tied together by a clean, intuitive interface... (Budget: $15 - $25 USD, Jobs: Database Development, HTML, MySQL, Payment Gateway Integration, PHP, SaaS, Web Application, Website Design)