I would stick with Mirallas for a bit yet, get some consistency in his game time and he might show some consistency. He's a much all round better player than Bolasie but he can't get a run in the side so when he does come in he's off the boil. He's got more goals and assists in him than Bolasie if given a run in in my opinion.
Rom apart, all of our forwards look devoid of confidence, except Bolasie as he's a guaranteed starter.