I adopted a Finch yesterday, please help ?

I adopted a Finch yesterday as my sister was unable to look after it. It's in my spare cage, which is quite large, big enough to house 3 tiels happily but I don't agree with keeping any bird cooped up in a cage for extended amounts of time. I let my 2 atiels out everyday and they both return to the cage when I want them too, as they are hand reared. They have a nice fly about in the lounge and I want the same for my finch, exept they are incredibly hard to catch ! I was thinking of letting him out for a few hours a day, buying a erfly net and catching him with that once I need him back in the cage but I dont know if it would stress the bird out too much ? Also I've been wanting to know what sort of finch he is. He's a very dark brown and the only markings he has is midnight black around his eyes and chest. He has an orange beak. I'm buying another finch tomorrow, as I've heard they need company.