[Freeswitch-users] Speccing server for enterprise FS

Looking to setup a new Freeswitch server that will be doing quite a lot of traffic. Trying to get a rough idea of where to spend the money (RAM? CPU? Network access?). There will be perhaps 10,000 simultaneous SIP registrations Maybe 500 simultaneous calls, some of (say 50%) which will require a-law to GSM transcoding. I know it's a tricky one to answer, but based on experiences here, which bits tend to glow first?