Personally, I like 2 wheel Trailers , the 1 wheel ones torque the bike, when the load is too tall..

2 wheel trailer will haul a bunch of stuff , potentially negating the need for any panniers
If you Don't want to get a new bike, I'd recc the 26" wheel..

.. though I really like my 20" wheel Bike Friday.. , packs up to fly across the 'Pond' easily.