Conventional or trunked?A win8.1 tablet with a (micro) USB port to connect your USB sound card will work fine. I'd recommend not using a dongle but a tapped scanner. The dongle needs a really strong signal for good decodes and you'll unlikely get this out and about. Plus you'll have a fiddly antenna to play about with.
I'm running an Asus transformer, an imic USB sound card fed from an ICOM r2. It works great. I picked the Asus for processing power and best battery life.