Staffing delima - what do you use?

I was recently assigned to create and maintain a resource pool of both on-shore and off-shore staff (75 total). As with any IT shop the environment is very, very fluid.

The goal is to assign staff to projects and support work based on skill sets and availability. I have been working with MS Project 2k but find it difficult to manage given all the variations on PM project plans. We are working towards standardizing but that does not help me now.

I am currently working it in Excel however it is not sophisticated enough to indicate "ripple effect" to downstream projects. What do you folks use?