I recommended the aquaclear because they work well for refugiums and there will not be a pump in the display. Up to you. I would use the 70 at a minimum. The 110s have a good amount of room which sounds what you want o keep equipment out of the display. I have owned a couple in the past. One was excellent, the other had a loud motor. Both worked very good though.
Completely get the cost issue so if you can live with the pump in the tank, go with the cheaper HOB.
Completely get the cost issue so if you can live with the pump in the tank, go with the cheaper HOB.