Jennifer said "Portugal has a complicated motorway toll system". She is being nice. It is more than complicated, even for a portuguese car if it has not the proper device, so you can imagine with a "foreign" car (just received a fine from "Via Verde" - toll system company - that's why I'm talking like this. Not a big fine, just 2,40 euros, but anyway). If you hire the car in Portugal then you have the proper device to go through all kind of toll sustems (yes, we have more than one) without problems.
Concerning your question, IMO the best option is the one that includes Barcelona. It seems more reasonable to me, and you have 2 extra days!