There are few companies that offer self scoring steel tip set ups. Dartsee and Fido Darts are a couple. However, they're more for a commercial setting and are quite expensive for a home user. When I first checked with Dartsee several years ago, they wanted something like $9k just to get a foot in the door. Fido Darts was cheaper at around $1500-$2000, but they're based out of Korea and again, are only interested in dealing with a commercial business.
Scolia offers a home system starting at just over a grand, it's been improved upon over the years and is gaining popularity (mainly in europe).
If you're dead set on steel tip, the most popular at home option that allows for online play is DartConnect. Membership is only $24 a year. It can be ran on most tablets, phones, and computers. Many leagues use DartConnect for scoring. However, it is not auto-scoring. You have to enter your scores manually each round.
If you're open to soft tip, Granboard is the most popular at home board with online capability. It's got the "fun games" that are anything but traditional darts, but also allows you to play against real humans online. The board runs around $300. You'll need a tablet to run the app. Last time I played, the app was free to use. Some "companies" offer Granboards built into cabinets... DIY is always cheaper.