I assume you've moved and chosen your provider by now, so I hope you chose well and you are online and live! but I wanted to confirm a few bits of information for you, that has been discussed, incase you never got the actual answer you are looking for.
SeeTheLight - these are the sister company of OFNL Networks, and was the first provider on the network. This was created to have a non-wholesale front for the company.
MTH Networks joined the network around 3 years ago, and we have been slowly accepting new customers as we build and develop our systems around OFNL. Our mission is to change the internet experience; and provide the best customer service. We've just dropped our prices across many packages, too. But I dont want to advertise, I simply want to answer your questions and try and help you make the best informed decision possible.
Every provider is limited to using OFNL Infrastructure, and so we do not have any control over it, and the engineers that are send out are from another OFNL-Sister company, GTC.
All OFNL providers should be able to provide Static IP Addresses, however - OFNL limit these to their business lines only, which they charge the ISP more for on a wholesale level. It is correct in thinking that realistically your home IP should very rarely change, as this is locked at DHCP for 90-days at a time, unless your router goes offline for longer than 2 hours.
"Business ISPs" are those that have not had further Company Checks. To be a Residential provider for OFNL, you have to undergo many checks and assurances with the OFNL team, so they can control and ensure the quality of their Residential ISPs.
If I can be of any more help, of if you have any more Network Questions - please feel free to contact me directly, or pop up on our Live Chat. As I said before; I'm not looking to advertise, you dont even have to buy from us! We're interested in making your internet and experience better, without any catch.
Your MTH Networks Team
ISP for BT OpenReach, OFNL & Custom Installed Networks