Tony,
We just recently purchased the SIMS product. We are still waiting to deploy it, however, I have some info you may find useful as we have a demo installed currently.
The SIMS product is a direct re-sale of netForensics. I recommend checking out there site, netforensics.com. Regarding your second question.
First, the SIMS product is completly modular, check netForensics site for more specifics. Basically you will have several components, a database server, an agent server, and a couple other servers. Now keep in mind depending on your config, these can all be on one physical box. We are splitting the agent server and the database server. The agent server runs some software that pretty much normalizes the events coming in from different devices, and then sends them off to the dB server. So the answer to your question is Yes, you will send your syslogs, or what ever type of logs to the "Agent Server."
Now from working with the product. The interface is great. It is all java, which I have to admit I was leary about, but they seem to have done an excellent job with it. The GUI is easy to work with. You are presented with a "desktop" that has a similar look and feel to a Linux desktop.
I would recommend getting with your Cisco rep, and have them get the netForensic folks out there to install and work with you on a proof of concept.
If you have any other questions please feel free to contact me, and I can get you in touch with my rep at netForensics.