Will my current mattress fit an electric boxspring?

That depends on both the material and the construction of your mattress. Pocket spring, latex and memory foam mattresses are suitable material-wise, with the exception of extra-firm mattresses, which don't flex enough with the hinged sleeping surface. With a 2-person electric boxspring, there's another factor: it has two separately adjustable sleeping surfaces, and a regular, unbroken 2-person mattress simply can't handle that. Not sure? Ask your local Revor retailer for advice.