Web app development

I'm about to start working on a large web app that is to be connected to SAP Business One.

This is something I'll be later installating on many costumer sites (on-premise) and in cloud environemnts.

My development platform is ASP.NET MVC (Visual Studio 2015).

Due to the solution targeted to small businesses (1-10 seats mainly), the target version of SBO is the SQL version.

I'm not sure which way to go in regards to the connection.

From what I understand:

• DI API is not recommended for use in web application (slow, unreliable).
• DI Server is being phased out, and there is no HANA version.
• The Service Layer is only available in the HANA version.
• B1i is only suitable for integration and not intended for my use.

I'm sure that for the next few years my target audience will not be using HANA but want to make sure I have a clear upgrade path to utilize it within 2-3 years.

How would you approach this.

Thanks, Dan