What's the best simulator for a CCVP?

I'm shortly going to be in a position where I won't have access to any equipment other than two computers, two routers, and two 2950 switches, which clearly isn't enough to work on a CCVP. I'm also just beginning work on this cert. Which would be the best online simulator for this? I'm not looking for the Cadillac of sims, either - just one that will do the job.