Microsoft (NASDAQ: MSFT) has launched new Office 365 business capabilities. The cloud suite, which features Exchange Online, SharePoint Online and Lync Online, could provide an ideal upgrade path for Windows Small Business Server (SBS) customers. But there are numerous Office 365 SKUs from which to choose. Which one is right for channel partners and their customers? The VAR Guy has a definitive answer. Here it is.

First, a little background: Microsoft effectively killed Windows SBS development in 2012. A potential alternative, Windows Server Essentials, really doesn’t offer apples-to-apples upgrade capabilities vs. SBS. So over the long haul, cloud-based applications like Office 365 could emerge as a preferred upgrade path for the aging SBS installed base.

But which Office 365 is right for partners and customers? The VAR Guy believes there are roughly 8 Office 365 SKUs from which to choose, ranging from super-small business options (1 to 10 users) up to enterprise users (50,000+).

Instead of being paralyzed by choice, The VAR Guy recommends Microsoft partners focus on this specific SKU: Office 365 Midsize Business, which is designed for 10 to 250 employees.

According to Microsoft:

And here’s the twist: Office 365 Midsize Business also supports Open, a new sales model that allows channel partners to manage end-customer billing for cloud services. That’s a key capability many partners have awaited. Now, it’s here.

Will SBS partners jump in? Hmmm…