Thank you for posting. Yes, you can definitely purchase any of our Office 365 plans. You can view/purchase that plan here. If you have any questions, reach out to our team. They'd be happy to answer any questions you have.
Just to clarify, we do not offer the ProPlus plan. We have: Email Essentials, Email Plus, Online Essentials, and Business Premium. While we are their partner, what we offer differs from Microsoft in some ways. In looking at the ProPlus plan on their website, the closest we offer is our Business Premium. You can see details about it in the link Heather posted above. Hope that helps!
Microsoft Sales Coordinator