What do low-tech, <10-person offices use these days?

I'm primarily a network engineer and have not kept up to speed on Microsoft technologies much in the past decade. Regardless of what I say below, the title is still my core question :)

I help a church with their technology. I deployed a WiFi solution, 60GHz bridge across the street, standardized on one model Dell PC for everyone, but the server is a really old Win 2008 SBS box. I want to come up with a scope of work for a MSP to do an upgrade and want to make sure the MSP is also following best practices (there are a lot of janky MSPs around)

Normally I would just deploy a new Windows Server but there is much more to consider these days. We've been using Google Apps for email since 2009. No AD integration, but that wasn't a huge deal as volunteers help out with email from time to time. Phone system is an ancient Nortel POS that nobody knows how to use, so perhaps we can jump into the Teams world. One of the people there pushed back on VoIP because "the switch has to be configured right." Why yes, QoS and LLDP-MED are a thing.

They have 8 domain-joined Win10 PCs, two network printers and need ~100GB of storage. They love network drives.

I was hesitant to use the cloud because it was cost-prohibitive to upgrade the cable internet beyond 5mbps upstream. However things are starting to look better in that regard as the phone company is ripping out DSL for fiber and Comcast is finally getting their business DOCSIS service out of stone age when it comes to upstream.