Question about how to design a web service

Hi all

I am currently creating a web service in ArcGIs 10.0. The service takes an address, geocodes it and addis it into a point layer to represent a client call request.

The question is about what is the best way to build this web service:
- Talk directly with SDE. I already have two batch VB.Net applications (.exe) that work very well doing that
- Use a map service or a feature service. In this case should I use Web ADF or javascript


Thanks