Best approach in query database and passing data remotely?

We want to write an application that query a database remotely. the received data could be xml, txt or image. we have our own server(server 2003_iis6). we can have our own appl开发者_JAVA百科ication on both clients and server. and we prefer to use C# .Net(but if Java is better we can switch to). size of our data is from a few bytes to 10Mb. average is 1Mb. what is the best approach?. we begin with web service but we don't need this much amount of compatibility. performance is our key problem. I have read about iis6 compression (gzip and deflate) and i know it can be enabled by iis manager (or metabas.xml) or into the code. Is RMI or Net remoting or WCF better solutions?. Why?. Is there any better solution?. I'm a Little confused with different variants. It is worth mentioning that our desktop application (both clients & server) do not have any html or asp page to display. we just have data to be transfer.

Start with WCF data services. WCF Data Services allows you exposing data access in form of REST services using OData protocol. Make a proof of concept and if it doesn't fit your requirements start custom development.