Hello there,
Let me see if I have it clear, it's a system with only management and billing, right? I mean, management of the clinic (rooms I guess), patient operations (charge, discharge, status, queries), billing (depending on the services), services, inpatient registration, store (Not sure if you mean it as a drug store or as storage management).
Now let me talk a bit about myself and my brother. We've over 5 years of experience working on Java, mostly working on maintaining / developing ERP (Enterprise Resource Planning Systems), which are the biggest you can find for enterprise management, covers from personel to production. In this case I could offer you a lower price (20% off) if you want to implement one ERP solution, which would be really really fast compared to developing one from scratch. If you want one from scratch just let us know.
Technologies that would be applied : Java EE with frameworks such as JSF/JSP (Primefaces + JSF), JPA, EJB3, iReports (As a reporting tool to produce pdf/spreadsheet files) and a PostgreSQL database sounds great.
Please provide me with further information in case you're interested in us making your software.
Thank you.