VOIP 3CX or ASTERISK new system or fix existing setup

I have a number of small companies Have simple IVR set up Use Speechelo to record all prompts Some extensions use Grandstream Voip handsets, others take calls direct to cellphones. Others want calls to Voip and if not taken etc quick diversion to cellphones. Some extensions want their inbound calls to be screened and announced to either Voip or/and cellphone. Some extensions require inbound calls to elect to remain in a queue. Some require inbound calls and or the IVR to handle call traffic by different time selections... examples calls outside of office hours are handled via different pathway. Some require unanswered calls divert to a real person extension during nominated times. Messages left in voicemail are emailed to party. Cellphone screened/announced calls as option is critical. Ability for faxes to be received via phone number and sent to nominated extension. The commonly used extensions must be re-recorded using Speechelo....so system-wide sounds the same. 3CX system currently resides un Vultr cloud. About 5 companies and different persons. Most use cellphones. Now.... we will pay AUD2500 plus freelancer fees.... plus require ongoing support at extra cost. Will make part payments but only when agreed modules work and tested to work. I dont have time to spoonfeed an inexperienced party... if you really know 3CX or prefer to switch us to Asterisk .... and can understand and have handled the requirements i have set up. .. this is for you.... for an absolute demonstrated example, will pay extra now. ..ie.... you show me you have this type of system working.... note.... a work around on the screened/announced calls for both Voip handset and Cellphone is compulsory.