Is a Dedicated Server Recommended for WebUI

I am planning a WebUI implementation, and wondering if I need a separate server. I am assuming that I will need another server with 8 procs and 16 GB RAM. There could be up to 20 concurrent WebUI users.

Here is the environment:

8000 endpoints

All the Bigfix servers are VMs whose hosts have Xeon E5-2660 v3 2.60 GHz processors
Root server 16 procs & 12 GB RAM
Bigfix SQL Server 8 procs & 16 GB RAM
BFI and Web Reports Server 8 procs & 16 GB RAM
Citrix Server for remote console access

3 head Relays - servers
1 failover relay - server
2 VPN and local relays - server
500 remote relays - workstations (mostly)

Seems over kill. Yes, you want it to be separate from your BES, but a VM is fine. Best practice is that it should be the same OS as your BES.