ASP.NET on SQL Server

I've been asked to quote for developing a system to expose data on a
web application. Most of the data will come from SQL Server DBs
located on a single box. However, some of the data will be sourced
from ORACLE which is located on a different box. It may be necessary
to create VIEWS and Stored Procedures joining these DBs

Does anyone have any pointers, clues, hints, tips or pitfalls that I
might consider while making my proposal? What sort of extra
contingency should I allow for the connection to ORACLE? Should I do
all the data retrieval on the DB server, or should I do it on the Web
server?

Any thoughts would be appreciated.

Thanks

William Balmer