Bill:
How about using a scheduling software like P3 (Primavera Project Planner) or P3e (Primavera Project Planner for the Enterprise)?
You might consider them expensive for your needs, but those are the ones I use and cannot talk about other software packages. With Primavera you can schedule your projects using diferent calendars, set up resources with diferent calendars and availability limits, allocate resources to activities, allocate priority to projects or activities, define resource leveling options, define leveling criteria and then resource level all your projects at the same time drawing resources from your company pool.
Are these the kind of things you need to do?
Tomas Rivera