I'm not on either at the moment, since I keep wanting advice over forums on different products, which is a very slow progress indeed.
Personally, if it were me, for aesthetic reasons, I would wait until the shed from you finasteride has finished and you begin noticing some regrowth before starting minoxidil. since you might have a more aggressive shed on both? I'm not sure about that, it's just a thought.
I don't know wether to suggest Nizoral or not, because I find it helps me quite a bit while I'm on no treatments, it seems to lessen my hair fall. Not sure if it would be worth using on minoxidil. do you intend on using a minoxidil. solution with a DHT blocker such as Azelaic Acid?