load-testing IIS

Hi All: I have a public webserver hosting one website that is on a 10Mbps
connection and receives about .5 page requests/sec and 20 requests/sec.

It's a Xeon 3.0 with 2 gig ram and 1+0 SCSI RAID.

We're anticipating a sudden spike in traffic to coincide with a promotion,
where the server will receive up to several thousand page requests per
minute for 5-10 minutes. The page being requested has been reduced to about
50K total including some 7 images on the page. There is quite a bit of
server-side processing on this page however.

Is there any way to accurately load-test the server in this scenario to
predict if it will be able to handle the load?