You are looking for a PBX , not a VOIP system.
On a PBX ,you could have up to several hundred,if not thousand of phone numbers that you could manage on your own, incluiding the sending out of fake caller I.D.
Such a PBX will need a minimun of one digital link to the outside world.
And will work that way only on the US. Some other countries do not allow you to send a fake I.D.
And will not be a cheap option neither.Will be looking at several thousand dollars minimun.