Hey guys, I'm trying to setup a cheap/free telephone system for a startup company I'm creating.

I need to have a service that provides a single phone number and then allows extensions to ring different cell phones.

Is this such a service? So someone would call this one line, which would have a recording and then provide extensions that would ring our individual cell phones?

I've tried google voice but it seems that it just rings everyone's phone at the same time.

Any ideas?
My Gear:
-Fender American 1962 Stratocaster Reissue
-1984 Marshall JCM 800 2204
-Ibanez Wh-10 Original
-Boss DS-2 Distortion
-Boss CE-5 Chorus
You would need some sort of call forwarding, but that only works line to line, so for each cell phone you wanted to have an "extension" for would need its own VoIP line in order for it to work, so basically it would probably just be cheaper to provide the cellphone numbers.
2011 Gibson Honeyburst LP Trad. w/ SD Whole Lotta Humbuckers
2014 Gibson Ocean Water Standard Plus
Marshall Haze 15W Head/Cab
Hughes & Kettner Tubemeister 5