I'm so glad to hear that you're coming to visit!
Without knowing what region you'd like to stay in, it is going to be hard to suggest an accommodation for you. Did you want a cottage, a resort, a hotel or a motel? Finding one with accessibility might be the easier part.
Some that I can think of right off the top of my head would be:
The Holman Grand Hotel located in the heart of Charlottetown.
The Delta Prince Edward Island also in Charlottetown on the picturesque waterfront.
Mill River Resort in beautiful western PEI.
If you go to the Tourism PEI website and look under 'Where to Stay' you can fine tune your search by region, type of accmomodation, length of stay, etc. and if you click on the advanced search option you can narrow it even further by choosing accessibility and other amenities that you might be looking for.
I hope this helps!