Difference between indoor and outdoor PV panels
As Olin Lathrop pointed out the durability of the panels is the major difference. If the final sensor is going to be placed indoors then considering the indoor panel is realistic.

First a comparison of efficiency based on the specs you provided: The indoor panel provides about 1.18 W/lux while the outdoor panel provides about 1.91 W/lux. If there is a concern over providing enough power for the application the outdoor panel might provide the extra power needed.

Next I took the efficiency numbers and combined them with cost to obtain a metric of (W/lux)/UnitCurrency. Since purchase volume has an effect on the price I have calculated the metric for both single unit volume and maximum discount. The indoor panel is about 46% less expensive than the outdoor panel at single unit volume. At 250+ units the cost difference reduces to about 18%. 

I would seriously consider the indoor panel if it would meet the power requirements. If the final sensor product will include a durable case, the argument for the indoor panel grows stronger.