I have a second phone number through Google Voice that forwards to my phone - it’s free, and I’ve had no problems with it. Seems like a simple solution to your needs.
I’m thinking of getting a web presence in a couple cities but no PHYSICAL presence. Could I simply get a Miami number (for example) and then optimize that number and simply forward it to my Cincinnati business?
I use a device from a company called Obihai and it works with Google Voice. The single line Obi200 costs $49.95 at Amazon, and the two line obi202 cost $99. I’ve had my cordless phone base station plugged into the older obi100 for several years with no issues, and I call my wife in Chicago for hours at a time, costing me nothing. I dial calls just like usual. The quality is, as far as I can tell, perfect (but then my internet here is a gigabit Google Fiber connection.)
One other lovely thing is that Google Voice filters out spam calls.
As long as they have a Miami number available. I tried to get a number in Seattle, but they didn’t have any available, so I chose one from the relatively-nearby Federal Way.
I don’t know about multiple numbers, but the single number I’m using is from an area code distant to my cell phone, and forwards just fine - voicemail picks up unanswered calls, I can use the Google Voice number if I want to make an outgoing call.