j@w, I like how you dis MyPBX and then punt your 3CX (I guess you're a reseller) , the major problem with 3CX is 1. it runs on windows based machine 2. there are licencing fees applicable based on simultaneous calls, for the price of 8 calls he might as well go for MyPBX or even FreePBX.
The SIP client on your cell is not unique to 3CX, you can use their free app to link to your asterisk systems.
How do you suppose the OP is going to connect the analogue phones he has to the 3CX box, ATA or interface cards or buy IP phones all at a huge expense.
I have been deploying MyPBX for a couple of years now and the only problem comes when you use ISDN and 9/10 times its because the incorrect codec was used uLaw/aLaw and the refresh interval, other that that it is rock solid - the support from the guys in China (Michael and Jason Chan) is always first class
The standard and pro version of the product can handle 100 extension and 22 simultaneous calls for a once off price.
I recommend the following:
1.
www.scoop.co.za and get a price online for what you need
- 1 X MyPBX standard or pro ( pro would be better if you plan to rack mount)
- 1 FXS module for every two analogue telephones you plan to connect ( 8 cards max = 16 analogue phones)
2. you don't need a dedicated outbound line per user, you can work on a ratio of 3:1 or 4:1 so for every 3 or 4 extensions you have you need 1 outbound line ( this ratio does not work in a call center environment)
3. you have various options when it comes to SP's
-either go for a pure SIP only account I know ECN offers these at a once off charge of R500.00 (15-20 simultaneous calls)
-or go for a gateway solution from ECN R999.00 which includes all hardware, IPC link (adsl) (15-20 simultaneous calls)