SDWAN Plus is not worth it. Enterprise is just a basic firewall and VPN license, Advanced lets you do more security features. SWPlus just adds outage detection of other networks, the value of which I do not see. Meraki Insight might be worth it, but I don’t think so.
Is there already an MX somewhere in the organization (is the site your going to VPN part of your organization)? All MXs in an org need to have the same license, so if there’s one already you’ll need to match it.
I have installed quite a few of them. All licenses allow both site to site and client based VPN. I install the base license most often. Advanced in about half. And I have never installed a SDWAN Plus. No need.
When I buy, I buy the Advanced Security license. It has absolutely helped us prevent intrusions, malware, and such. I discovered one of our people had a cell phone that had a bank-info stealer built into a card game on their phone because her phone was on the guest wifi and Meraki picked it up.