When I talk to UC provider (or Hosted VoIP providers) that sell nationally, the biggest challenge is the customer install. There are a couple of national installers including Endeavor. The feedback I hear is that the current choices are not good. just because you can spell ROUTER doesn't mean you can configure one or find one was just one anecdote.
One thing I keep thinking is that there are a lot of VARs, MSPs and Inter-connects throughout the country who would like some of that site survey and install revenue. Now, I know that not all of them have the skill set to perform these functions any better, but there may be an answer.
NETX USA already distributes a lot of VoIP CPE and configures phones for VoIP providers. NETX USA likely has a database of companies that buy equipment from them (many of whom are probably VARs or MSPs or Inter-Connects). This database of techs could be the answer to the nationwide installation problem.
FreedomIQ sells through a dealer channel that also does the install. Ideally, the channel partner would sell, install and support the customer. Ideally. We don't live in an ideal world.
ScanSource would be another possibility for a dealer network. I think that if the dealer bought VoIP gear from ScanSource and could pass a certificate program then that network of technicians could work too.
I'm not sure if the VADs - Tech Data or Ingram - have a dealer network that would work because these distributors sell software and hardware to anyone. VADs aren't concentrated in the VoIP vertical.
EarthLink's CMO told me that they use a group of techs that grew out of New Edge Networks for installation. But can even they be everywhere?
I have seen MegaPath trucks. The RBOCs have lots of technicians (and sub-contractors) nationally. The cablecos have technicians and sub-contractors as well. I have no idea what other carriers do - like Cbeyond.
There's always Geek Squad by Best Buy.