I would recommend getting a Google Voice phone number. You can use the number to follow you anywhere, your cell, your home, office, etc. It doesnt matter which phone service you use or how many times you change vendors, you always own your phone #.
For a SOHO like yourself I would probably go with one of the more simple like Vonage, they offer SOHO plan. Ring Central is also pretty good. They both offer features above and beyond basic calling, like voicemail to email service and online call logs.
Hope this helps!
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