Generating Overnight Data Vs Live - Suggestions Needed.

We have an MIS system which has approx 100 reports. Each of these
reports can take up to several minutes to run due to the complexity of
the queries (hundreds of lines each in most cases). Each report can be
run by many users, so in effect we have a slow system.

I want to seperate the complex part of the queries into a process that
is generated each night. Then the reports will only have to query
pre-formatted data with minimal parameters as the hard part will have
been completed for the users when they are not in. Ideally we will
generate (stored procedure possibly) a set of data for each report and
hold this on the server. We can then query with simpler parameters
such as by date and get the data back quite quickly.

The whole process of how we obtain the data is very complex. There are
various views which gather data from the back office system. These are
very complex and when queries are run against them including other
tables to bring in more data, it gets nicely complicated.

The only problem is that the users want to have access to LIVE data
from the back office system, specifically the Sales team who want to
access this remotely. My method only allows for data from the night
before, so is there an option available to me which will allow me to
do this ? The queries can't be improved on an awful lot, so they will
take as long as they take. The idea of running them once is the only
way I can see to improve the performance in any significant way.

True I could just let them carry on as they are and let them suffer
with the performance on live data, but I'd like to do something to
improve the situation for them.

Any advice would be appreciated.

Thanks

Ryan