Yeah, that's quite small. A piece of stripboard/protoboard would need to be no more than 14x15 holes, I think. Are you certain these components will fit into that space in any configuration?
Pro Mini is 13x7 holes, I think, so that takes up half the space by itself...
Depending on the design of the Pro Mini you are planning to use, the A4 & A5 pins may not even be on the 0.1" grid of the main rows of pins, forcing you to use wire to connect to them to the rest of the board.