I think I have installed Team System SKUs without project, but I am not 100%
sure. If you have purchased a Team SKU, however, you have Project, as it is
part of MSDN. The main reason for project is the Office integration stuff,
but it is also available for other Office products. The Team bits should not
install if does not pass pre-reqs, so try it and see.

You might end up with a licensing issue, however, with simply installing
Team Explorer on Professional, so I would examine this option carefully. I
know it saves to have the Explorer and not the Team SKU, but it might not be
a valid option from a licensing standpoint.

If you are an ISV, consider certifying a few applications (PocketPC and
SmartPhone apps are relatively cheap) or getting client recommendations. At
only 50 points, you get Certified partner and 5 copies of Team Suite for the
partner fee. At gold cert. partner (120 points), it is 25 copies.