Different Rate Limits per Port based on IP?

We use C2950 switches with EI and are successfully rate limiting on individual ports. Now we have an additional need.

We are running virtual servers (multiple guest machines running on a single physical host). The physical host plugs into a single switchport. For example, assume 5 guest machines:

VM 1 - 10.1.1.1 VM 2 - 10.1.1.2 VM 3 - 10.1.1.3 VM 4 - 10.1.1.4 VM 5 - 10.1.1.5 Physical host - 10.1.1.6

We want each VM to be rate limited individually. Example, each VM should get 1 Mbps. In other words, rate-limit based on source IP.

If we just rate limit the switchport to 5 Mbps, a single VM could pass up to 5 Mbps traffic. Goal not met.

I know the 2950 has very few rate-limit options compared to a router or a 3550.

Is there any way to accomplish what we need on the 2950? If not, what is the minimum switch model we'll need to do this, and will we need SI or EI image?

Or is it better in the long run to go with a router to rate-limit based on IP address?

Advice, please. TIA.