Get your stuff working on Concept IIs as well as your own ergometers. Just do it. Seriously. If your subscription business depends on selling your customers your own ergometer first, you'll have a very steep barrier between you and success.

Recent models of the C2 monitor have connectivity features.

There's an opportunity for remote-community features for indoor rowing like what Zwift offers for biking. And you won't have to deal with shipping heavy stuff to every customer before they subscribe.