Server config for hosted platform

Okay, so everyone has their opinion of what hardware config is required for Asterisk with Free PBX for my hosted solution. I have 4 slices of VMWare so what should my SERVER look like for optimal performance. I have about 200 extensions on each one and have anywhere from 50-60 concurrent calls across all 4. How many concurrent calls can Asterisk 1.4 really handle. Yes I do have a bunch of DSS/BLF running and VM and IVR.
Thanks everyone

Meant a total of 160-200 concurrent calls across all 4 total, sorry about that.
And I am growing everyday! :slight_smile:

Start with

for your call volume using standard codecs, you will need an impeccable 20mbs internet connection.