I have a client running school (10000 students). we already had windows hosting account with 5GB disk space and 15GB bandwidth / month.
the average hits per day is less than 200.
the hits may be around 20000 when we publish results (three times in a year)
at this time, current hosting shutdown automatically because my account reached allowed resources at that time.
also, we are planning to host web based student database management system along with student results.
It might be worth looking at a VPS / Cloud based solution that will allow you to scale the resources up during the peak times.
Buying a smaller package, would probably allow you to save some money during the quieter times, then, when you need it during the peak time you pay for a package boost and double your resources to cope with the extra demand.
you should go with VPS hosting. But during selection of a host you must concentrate on Reliability, Usability, Customer Support and then of course price. These are on some of the key requirements of a good web hosting company and compare them, the choice becomes much easier.
That is something that end user will never be able to test beforehand. What you need to do is try to understand that.
In this stage I believe that is important to find the solution within your budget and configuration.
Goof luck.
