Both need 5 V. The Pi needs about 3 Amps. The screen needs between 0.5 and 1 A, depending on brightness. So I figure I can power both off of a shared 5 V power supply as long as it provides at least 4 A. But I can't find a 5V 4A power supply. So I'm wondering... could I just wire two 5V 2.5A power supplies in parallel? Would this work? I feels wrong but I can't think of why.